Just how many songs are in your iTunes lib? ;-)
305 albums, 19.5 days worth of listening time, 43.66 GB. This is after I trimmed out albums I stopped listening to; my library used to top 75GB.
Regardless, iTunes 8 is not 64-bit while most of Snow Leopard is. Even Safari is 64-bit. Heck, even Finder is 64-bit now, after it was completely rewritten in Cocoa. iTunes needs the same treatment. A total rewrite in Cocoa, clear out all the old code, slim its memory footprint down, improve its performance (especially when loading album covers in Grid and Coverflow views), etc etc.
iTunes needs the update. I hope iTunes 9 delivers it. Probably won’t, though.