nah mate, though you could try a few of the other msn messenger plugins:
I dont think Toaster 0.5 was compatible with winamp 2, it would have been a documentation error. Winamp 5 is required to do the %artist% type processing for custom formatting. Earliar versions of Toaster werent customizable or have the msn messenger support.
Ive seen a couple people claim winamp works without a plugin, but Im guessing those people have installed some msn messenger package thing which has installed one for them. There certainly isn't any support built into messenger or winamp for this out of the box.
You might like to give winamp 5 a try. If the freeform skinning etc turns you off (as it does for me, but I did like the idea of a notifier), you can just turn it off and delete the plugin which makes it possible (gen_ff.dll). The devs realised people prefered the 2.x series and basically made winamp 5 an upgrade to 2.x, with all the extra bloat crap being implemented as a plugin/s instead, which can be removed quite safely. Just get the lite version and it wont have that crap, though Toaster and Winamp make good use of the Media Library for better performance and features so you might want to get the full and cull it back manually.