yes, it's just you... and you CAN switch to another app while starting one up:
1. if you've got one that's slow and you know this just start it, snap to the side then use what you want or switch to desktop with win+d or whatever (but TBH i NEVER shut down the mail app or outlook)
2. you CAN switch to anything, apps start in the backgroud just fine
Hmm... the Metro app startup seems to just hang there if I switch to another application in the middle of it, and when I returns after five minutes it still greets me with the whirling circles. My company notebook is 1280x800 so I cannot use the "side-view" feature, but for my work desktops with greater resolutions and the "side-view" thing, it still behaves the same.
and saying all metro apps suck so bad then giving one example wich is pretty subjective (my mail app starts up around 3-4 secs) is not a good way to start an argument - but plenty of the metro apps suck, buggy or lack features i give you that
1. it will change with time, MS itself stated that they'll continually update their metro apps
2. all app stores are alike in this respect: 90% of the stuff is utter crap, deal with it and find your preferred 10%
well I can list all those Metro apps one by one, like Weather, Finance, People, Message, whatever. They all start much slower than their desktop counter parts. And harder to use. And those are Microsoft's own apps. It's not like third party apps we are talking about here, and even the Store app itself is slow and acting weird at times, this does not even come to the third party apps in the stores yet. I think one example should suffice here already, it's really about the Metro apps in general, I don't need to point out the names one by one.
And I'm using the genuine TechNet RTM version, not some preview releases. My team's clients want to test their products under Windows 8, so we are provided some licenses, and even a couple (really awful) Windows 8 tablets to work with.