The issues appeared to be related to verifying the AppleID. The stores were up, you just couldn't buy anything because you could not authenticate, which is the single point of failure. It didn't affect the developer log in though.
The only reason it was removed in the MB is because they didn't have room for it. The MBP will probably keep all its ports so there is no reason to combine the USB with the charging. Plus, with the MBP there is probably going to be a lot of charging under heavy professional use so more chance of tripping on the cable. I see the MB as a charge overnight and go, just like the iPad. Less chance of tripping.
The whole magsafe argument is irrelevant because, although it was a brilliant idea, it was born from the necessity that MBP required being plugged in all the time at, classrooms, coffee shops and airports. Now, no more hard drives spinning, no more fans, energy sucking CPU, or dvds. You just charge it up at night and go all day just like your iPhone or iPad, hence no more magsafe necessary.
The slimness is for on the go. The design is irrelevant when you are sitting at your desk where you might need a dongle. When you leave the office, you leave the dongle there too, just like a dock. The battery lasts all day. It is not like it will be on the charger all the time. The USB port will pretty much always be available in the rare instance when you need to plug in a flash drive while out and about. Seems perfect for college students. Personally, I have the rMBP...