I'm thinking of a getting a 20 inch iMac (switching from PC), but I noticed the MacRumors buyer's guide says iMacs are due for a refresh pretty soon. My first question is: What sorts of improvements is the refresh likely to bring, and are they worth waiting for? I'm mostly interested in doing some sound & video editing, watching DVDs, word-processing, surfing the internet, etc. Gaming isn't really my thing, so if all we're likely to see is a new GPU (7600gs, maybe?) or something along those lines, I'll probably just bite the bullet and order an iMac now. And my second question: Does the CPU in the 20 inch iMac run hot? I just spent a few hours "researching" (i.e., staggering ineptly through hundreds of Google results ) Core 2 Duo temps in general, and it seems that anything much higher than 60C is going to shorten the lifespan of your CPU. Do iMacs run cooler than 60C? I plan on doing video conversion and the like, so I expect my iMac to be under load quite often. Third question: How do you guys deal with dust build-up in your iMacs? The good thing about having a regular PC is that you can just open the case and blow the problem-areas with compressed air. Seems like this wouldn't be an option with an iMac, so my concern is that it'll run hotter and hotter over time as dust builds up and blocks the vents. Fourth (and final) question: Will it be possible for me to upgrade the optical drive down the road (e.g., when slot-loading Blu-ray/HD-DVD drives become cheaply available)? TIA for answering my questions.