Even 1.89d4 with 11.01 doesn't seem to run reliably, at least for me it crashes or freezes way too often, and sometimes doesn't want to play music at all, where 1.88 with the last 10.x version of iTunes was working seamlessly.
MacMini (mid2010) with abundant RAM, running OS 10.8.2, and nothing else... Desperately waiting for PM 1.9, in hopes that that fixes the issue and brings back normal operation and functionality...Or iTunes 11.1, or whatever it takes. If you haven't upgraded to iTunes 11, wait a bit longer.