The amount of Apple fanboyism on this article is amazing.
I use IMAP. I like IMAP. With a decent client (Thunderbird), it does a pretty good job at handling email.
It is not, nor has it ever been, serious competition for Exchange/Outlook. If you don't work someplace that needs groupware, you don't understand. That's OK. But at any large (or even medium) business, it's impossible to get anything done without groupware.
How do you schedule a meeting with 10 people? How do you find a time when everyone is available? How do you know who's going to attend? How do you keep on top of all of the things you have to do?
This is the RDF at it's best. iPhone doesn't support 3rd-party apps? They weren't important anyway. Shared calendars? Who needs them! IMAP IDLE? No, we should all use the draft Push-IMAP standard that was deprecated in favor of LEMONADE!
DirectPush just works. There aren't five servers to configure. You don't need separate software to enforce security settings. Like BlackBerry, it's a fully integrated system that requires very little babysitting. Unlike Blackberry, it doesn't have a central point of failure.
DirectPush means that I can sleep an extra hour when my manager cancels the weekly status meeting. DirectPush means that I don't ask stupid questions that were already answered in an email I just received. DirectPush means that I can set reminders on my desktop and they just show up on my phone. It means that my contacts are backed up, automatically and transparently.
Millions of people use BlackBerrys or DirectPush. They're going to continue to do so until Apple realizes that it's about more than just email.