That's where this guide comes in. I've gone ahead and compiled the information I've gather while investigating TNT2 card offerings from several companies. I was going to do something similar for 3dfx's Voodoo3 cards, but decided that since their merger with STB, there just isn't much to report on this subject. (but I may throw something together at a later date)

Here they are, in no particular order, a (fairly complete) run-down of announced NVIDIA TNT2 powered cards and their features:

AOpen PA3010
	AOpen is offering two options to TNT2 buyers. The PA3010-A features 16 MB of SDRAM, while the PA3010-N features 32 MB of SDRAM and TV-out capabilities. The two card available from AOpen both ship with the standard 125MHz TNT2 chipset and RAM running at 125MHz, however, AOpen has reported the ability to overclock the card to 140MHz/170MHz respectively.
AOpen PA3010-A Features:    Memory: 16 MB SDRAM    Price: Unknown    Included Software: Clock Tuning Utility    Bundle: Unknown    Other Features: N/A    Clock Speeds: 125MHz TNT2 - 125MHz RAM AOpen PA3010-N Features:    Memory: 32 MB SDRAM    Price: Unknown    Included Software: Clock Tuning Utility    Bundle: Unknown    Other Features: TV-out    Clock Speeds: 125MHz TNT2 - 125MHz RAM Links:    AOpen PA3010 Page

ASUS AGP-V3800
	ASUS looks like they are offering TNT2 buyers a wide variety of options. Standard on all ASUS AGP-V3800 cards is 32 MB of SGRAM, but with optional features like Video-in, TV-out and support for their 3D Virtual Reality glasses, ASUS is offering everything a gamer wants.
AGP-V3800 Pure Features:    Memory: 32 MB SGRAM    Price: Unknown    Included Software: Unknown    Bundle: N/A    Other Features: N/A    Clock Speeds: 125MHz TNT2 - 150MHz RAM AGP-V3800 TVR Features:    Memory: 32 MB SGRAM    Price: Unknown    Included Software: Unknown    Bundle: N/A    Other Features: TV-out, Video-in, VR Circuit    Clock Speeds: 125MHz TNT2 - 150MHz RAM AGP-V3800 TVR Deluxe Features:    Memory: 32 MB SGRAM    Price: Unknown    Included Software: Unknown    Bundle: N/A    Other Features: TV-out, Video-in, VR Circuit, 3D Glasses    Clock Speeds: 125MHz TNT2 - 150MHz RAM AGP-V3800 Ultra Deluxe Features:    Memory: 32 MB SGRAM    Price: Unknown    Included Software: Unknown    Bundle: N/A    Other Features: TV-out, Video-in, VR Circuit, 3D Glasses    Clock Speeds: 150MHz TNT2 - 183MHz RAM Links:    Asus AGP-V3800 Press Release

Diamond Multimedia Viper V770
	Diamond has recently decided to offer two varieties of TNT2 powered cards. The Diamond Viper V770 uses the standard TNT2 chipset and offers a 125MHz engine clock with 32 MB of RAM running at 150MHz. In addition, Diamond will also be offering the Viper V770 Ultra, which will use the TNT2 Ultra chipset running at 150MHz and 32 MB of RAM at 183MHz.
Viper V770 Features:    Memory: 32 MB    Price: $179.95 @ Amazon.com    Included Software: InControl Tools 99, Zoran SoftDVD    Bundle: See Page    Other Features: N/A    Clock Speeds: 125MHz TNT2 - 150MHz RAM Viper V770 Ultra Features:    Memory: 32 MB    Price: $249.95 @ Amazon.com    Included Software: InControl Tools 99, Zoran SoftDVD    Bundle: See Page    Other Features: N/A    Clock Speeds: 150MHz TNT2 Ultra - 183MHz RAM Links:    Diamond Viper V770 Page    Diamond Viper V770 Ultra Page

ELSA Erazor III
	Hailed as having one of the most economical and best performing TNT cards, ELSA looks to continue this history with the Erazor III. Coming in three varieties, the Erazor III should offer the buyer flexibility when making their descision. Of note is the Erazor III Video, which is targeted for towards people interested in doing video editing, and includes ELSA's MainActor video editing software.
Erazor III 16 MB Features:    Memory: 16 MB    Price: TBA    Included Software: ELSASettings    Bundle: TBA (Full Retail Game and 3D Game Demos)    Other Features: N/A    Clock Speeds: Unknown Erazor III 32 MB Features:    Memory: 32 MB    Price: TBA    Included Software: ELSASettings    Bundle: TBA (Full Retail Game and 3D Game Demos)    Other Features: N/A    Clock Speeds: Unknown Erazor III Video MB Features:    Memory: 32 MB    Price: TBA    Included Software: ELSASettings, MainActor, NetMeeting    Bundle: TBA (Full Retail Game and 3D Game Demos)    Other Features: Video In and Video Out    Clock Speeds: Unknown Links:    ELSA Erazor III Page

Guillemot Maxi Gamer Xentor
	Guillemot has a history of impressive 3D cards, and their next generation is no exception. Guillemot, like many vendors, has decided to ship several varieties of TNT2 powered cards. On the low-end, the Maxi Gamer Xentor will feature a 125MHz rendering engine, w/16 MB of 166MHz SDRAM. On the high-end, the Maxi Gamer Xentor 32 will house a screaming 150MHz rendering engine, w/32 MB of 183MHz SDRAM to back it up.
Maxi Gamer Xentor Features:    Memory: 16 MB SDRAM    Price: $149.99 ($20 Rebate Offer)    Included Software: XingDVD    Bundle: Playable Demos    Other Features: N/A    Clock Speeds: TNT2 Unknown (125MHz ?) - 166MHz RAM Maxi Gamer Xentor 32 MB Features:    Memory: 32 MB SDRAM    Price: $229.99 ($30 Rebate Offer)    Included Software: XingDVD    Bundle: Playable Demos    Other Features: TNT2 Unknown (150MHz ?) - 183MHz RAM    Clock Speeds: Unknown Links:    Guillemot Maxi Gamer Xentor Page    Guillemot Maxi Gamer Xentor 32 Page

Hercules Dynamite TNT2 & TNT2 Ultra
	Hercules has a wide variety of TNT2 products planned. The first that should be publically available will feature a TNT2 chipset with 32 MB of RAM clocked at 175MHz/200MHz, respectively. You can expect features like TV-out and a DVD solution on other offerings from Hercules.
Dynamite TNT2 16 Features:    Memory: 16 MB SDRAM    Price: $149.99    Included Software: Hercules Power Drive    Bundle: None    Other Features: N/A    Clock Speeds: 145MHz TNT2 Ultra - 170MHz RAM Dynamite TNT2 32 Features:    Memory: 32 MB SDRAM    Price: $199.95    Included Software: Hercules Power Drive    Bundle: None    Other Features: N/A    Clock Speeds: 145MHz TNT2 Ultra - 170MHz RAM Dynamite TNT2 Ultra Features:    Memory: 32 MB SDRAM    Price: $229.99    Included Software: Hercules Power Drive    Bundle: None    Other Features: N/A    Clock Speeds: 175MHz TNT2 Ultra - 200MHz RAM Dynamite TNT2 Ultra TV Features:    Memory: 32 MB SDRAM    Price: $245.99    Included Software: Hercules Power Drive    Bundle: None    Other Features: TV-out    Clock Speeds: 175MHz TNT2 Ultra - 200MHz RAM Dynamite TNT2 Ultra DVD Features:    Memory: 32 MB SDRAM    Price: $249.99    Included Software: Hercules Power Drive, DVD    Bundle: None    Other Features: TV-out    Clock Speeds: 175MHz TNT2 Ultra - 200MHz RAM Links:    Hercules Dynamite TNT2 Page