In general I think that Apple should be saying to developers, 'we want our 30%' because it's their store, their revenue stream and it's pretty transparent, but when this kicked off with Dropbox I said it then, it's really stupid. If it's a case that they're selling the subscription through the device then fine, take the 30% charge, however if it's a case that the subscription is setup outside of the iOS store, off the device then Apple needs to go "oh well".
EDIT: mea culpa, mea maxima culpa. It sounds like Microsoft has removed the subs options from their app and resubmitted it to Apple who have yet to approve it, not denied it. It sounds like Microsoft have leaked that they were waiting in some attempt to look like Apple is picking on them.
That's the way it works though - I have a subscription to DropBox that I setup outside the iOS store, and I'm pretty certain that Apple didn't get 30% of that subscription fee.
Apple blocked Dropbox from the App Store until they removed a link to IAP from their native client. Dropbox finally relented and removed IAP from their native client and the application was allowed in the App Store. I'm (reasonably) confident that as soon as Microsoft removes IAP options from their Skydrive native client, that, they too will have their app approved for the App store (presuming they pass the other conditions).
Do you have a reference for an agreement between Apple and Dropbox? My take on the whole thing is that Dropbox is operating exactly by the rules by not offering an IAP option nor link to outside subscription purchase from within the app.
True, it could be Microsoft spinning it to make Apple look bad, they might be trying to push against the rules, so if I turn out to be off the mark I'll mea culpa.
EDIT: mea culpa, mea maxima culpa. It sounds like Microsoft has removed the subs options from their app and resubmitted it to Apple who have yet to approve it, not denied it. It sounds like Microsoft have leaked that they were waiting in some attempt to look like Apple is picking on them.