2.91
Development on 3 has for the most part stopped. Nullsoft is currently the process of bringing Winamp 3's plugin AND free form skin API to Winamp 2. The working name for the new player is Winamp 5 (2+3=5

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Winamp 2.91 already brought in the Media Library (great feature!) and Video support that 3.x has. If you don't want them, just disable the plugins.
2.95 beta, soon to be released, has a CD ripper built into the Media Library, uses LAME to encode to MP3.
Later releases will begin to introduce Wasabi (WA3) plugin support and free form skins. All via plugins of course, just disable/delete the plugins if you do not want the features.