I'm going to buy one of these two computers, either an iMac or a MB (don't need it to be Pro). In either case, I'll be waiting for the Penryn update (any clues? some people saying it'll be some time between early February and late May - I can wait). Most of the time, I'll use my new Mac as a desktop, so iMac seems to have more chances to be my pick, because of the bigger screen. However, I'll occasionally need some mobility, which would support the idea of buying a MB, but the screen is smaller. Is it possible to link the MB to an LCD/TFT screen when using it as desktop? That would move the balance to buying a MB, since the other specs would be quite similar. What about battery life and head in MBs?