Just because Flash is single threaded and thus can only choke one core of a dual core machine at a time doesn't mean it can't bring a 2.8 Ghz machine to it's knees. Just try watching one hulu movie in Safari in one window and load some particularly crappy flash game in firefox. Your machine is now unusable.
Adobe treats mac users as second class citizens thus treating many of their power users like dirt. If you think like Steve Jobs, this is an insult to Apple since they went and did want industry members like Adobe have long demanded of them and built a better OS than Windows (much better) and built really solid hardware, the iPod Touch/iPhone anyways, and then been plagued with monopolists like Adobe/Microsoft shutting them out. If history is a lesson, (think iWork) Apple will soon deliver a native version of Inkscape and dump resources into Pixelmator, and start bundling them with Final Cut studio and new iMacs (well a trial version in Pixelmator's case). Apple somewhat reasonably demands more, Adobe and Microsoft refuse to/can't deliver so Apple just raises the bar... this is capitalism at its best; even if the Google Voice fiasco is capitalism at its worst.