Over the past few days I haven't noticed much. However, I downloaded Firefox 3.5 this morning and everything has been good, except for YouTube, which has gone to shit. About every other video fails to load and suggests I try again later. However when I load YouTube on my backup browser, Safari 4, it works just fine.
Youtube has been really going all quirky on me recently, both slow and simply not loading at all.
And since the new Firefox came out, the thing has been crashing randomly, and not the easy type of crash, just "BAM! It's gone sucka! You wanna report dis fool?"