Too bad Jobs put a bullet through Apple's head in the enterprise space by canning the XServe. RIM salespeople were dancing in the streets that day, when the Playbook suddenly went from vaporware to roadmap.
what sort of enterprise are you talking about? Any enterprise worth getting 5 senior sales/marketing execs from RIM is not one that buys Xserves as a core data center technology (most of these shops are 'tolerating' *nix now, with a Mainframe in the back room, and a slew of Windows Server 2003 blade farms throughout).
Apple wants to sell an iPad/iPhone and a Mac Desktop/MBP to every employee in the company. The IT department will fight that tooth and nail, just like they fought Blackberry's for years. These 5 people will sell to the users and force CIOs to support them.
Apple's integration with Active Directory is more important than Xserve. Integrating into central configuration is more important than owning the webtier.
If Sun couldn't take over the data center, how do you think Apple will fare any better with a 'data center centric' attack. No, the 'long pull' plan is to own the desktops, then invade the server room (as we saw Microsoft do circa 1990).
The Apple modus operandi is selling phones and pads to sell desktops. Halo Effect. It worked with iPods 5 years ago on college campuses... With instant connectivity the key force multiplier (no calling back to the office or texting somone for data), getting every 'sales/knowledge-worker' mobile access to the data is key, and putting on a device that eliminates either a laptop or a phone (or both) makes total sense.
The next logical step is figuring out how to sell Apple OSX Server software into virtualized environments, which is what real enterprises want (remember, they haven't gotten rid of exchange, so they're gonna have dozen's of exchange machines.... ). This puts a foothold into owning the most important part of the halo, the web-app tier. Much like how hard it is for Lotus Shops to give up Notes database apps, once you lock in into web development on OSX server optimized for safari on your device farm (think IIS and IE), you've got a toe hold to the enterprise.
Blackberry has no such hold... their BES boxes were nice utilities to link to Notes and Exchange Servers, and they have no DNA for enterprise apps. Apple's has that DNA (again see the reference to NeXT and WebObjects, and the scale of their commercial websites and online services).
I see the plan... I've seen it before. Jobs has read Ballmer's book.