Apple Mac App Store: A Question

Of course (how could one avoid it) everybody has seen that Apple opened their new Mac App store today.

What do you think about it? Will it be success? What magnitude? Why, why not?

Pro:
*Cheap s/w
*almost zero cost for authors, rev. split with Apple
*"Apple" branded == walled garden with nice people in it only, you can trust the Steve--he's on of the Steves!
*access to new market with little risk for authors
*yet another iTunes store extension
*market seems to accept this new channel strategy--is credible for tech. and "quality" reasons. Apple takes "permission" to yet another level. it was sort of "necessary" for iPhone...now it just plain seems like a good idea that works
*expectation set for cheaper, single use apps thanks to iPhone apps...utils, gimmicks, games. spectrum from "flashlight noisemaker to "Angry Birds""
*cloud is OK for everything now! Netflix, Apps, what next? your whole iTunes library?
*add'l value in the free updates (presuming that carries over to Mac Apps)
*new route for shareware/freeware to monetize? I'd "buy" OpenOffice from the App Store if it was cheap enough and I felt the $$$ were going to the good guys?

Con:
*not filling an empty niche?
*s/w market already had distinct monetization/channel schemes?
*low prices...and share revenue with overlord Apple?
*value stack not special/unique/required as it was for iPhone?
*expectations different for s/w on computer vs. portable device?
*if a failure, black eye that injures the Apple teflon coating.

If this is such a great idea, why didn't Microsoft do it already? Guys like Digital River have done it as the "back office" for many vendors and authors already. What's the big deal? Why didn't somebody else do this...one the big mail order houses that made the seen for PC and Mac back in the day?

Paging Mr. Porter, your "5 Forces" are required...paging Mr. Porter...