My dad was going to take me to buy an iMac tomorrow, but I'm not sure if this is the right time to buy. I've been seeing talk about "bumps" in February? Would a "bump" be a upgrade or a change in the entire iMac. I don't want to buy the iMac and then have a new one come out in February. Then again, I don't want to wait for an update in February just to find out nothing has changed and then have the update come in March... Any opinions on when to buy? 