Since when did S3/Diamond stop doing drivers for the Viper II.
Those of you who instantly have rushed in and said they have stopped are obviously full of it and love your V3's. <- oh BTW, can you say 32-bit colour? No, didn't think so.
The last driver update from S3/Diamond came this very month and there is no reason to suggest that they will not keep coming. Also, S3 haven't completely pulled out - they are still planning to carry on their very high-end graphics chipsets and will also need so support VIA with their integrated North-bridge/Savage chipset, and for the moment haven't announced an end to new driver releases for any cards.
While I will admit the future looks bleak for any S3 cards after Win2k passes by, the ViperII is not a bad card and many of its flaws have been fixed. Oh and the T&L unit does work in D3D and OpenGL, make sure you have the latest drivers.
As for speed, the ViperII is faster than the V3 and it even has Metal, which is S3's own super-fast API (a bit like Glide). Also has S3TC/DXTC so in terms of future games, it should stand up a little better. As for 2D, this is one of S3's stonger points and DVD quality from S3 cards has always been good (on the Matrox/ATI level). Also, if you download a set of tweaked drivers, you can even try playing around with FSAA/supersampling (not recommended, due to card having lack of performance).
The Voodoo3 on the other hand is also no slouch, and while not faster than the ViperII, it has a lot of support out there from programmers, etc., and of course Glide.
As for Deeko's suggestion to get the V4, not a bad idea that - it has suitable performance for any of today's games and also has the texture compression features, etc. and while not as fast its bigger brothers, it should be a good card (if the price drops!!).
To sum up, if you want the gamers card (despite being slightly slower), get the V3, as it will do its job perfectly well. If you want the total package card (ie. more features) then consider the ViperII. Either way, its your call.