No need for knee-jerk "lols", it makes a lot of sense.

For one, it will force most of them to download the Gmail app.

Second, those iPhone users don't benefit Google -- Google needs to control the experience, the ads etc in order to make money off them.

So, you have users who have years of e-mail in GMail, use GMail for free, use their @gmail.com everywhere, and probably don't know how to migrate their e-mail to another provider.

Give them a choice: (1) go through a messy migration or (2) install another app. Most will probably do (2) without even thinking about it.

And then you have to factor in that worldwide, over 80% of the smartphone users already have a platform where GMail is the default mail app:

http://www.idc.com/getdoc.jsp?containerId=prUS24442013

20% of a big pie is still pretty big.

I think they'd definitely do it. Google has decided to flip the switch and monetize as much as possible lately, having to use the Gmail app would be in line with that.

The benefit of gmail to Google is the intelligence gained for targeted marketing by scanning your email.

The worry that Google will disable IMAP misses this point. Google gains so much ancillary intelligence from scanning your email, that if they lose market share, their overall ability to target unrelated ads (e.g. during search).