As long as MSFT has no serious competition in that area, they will be a viable company. If Apple wants to kill the MSFT-dragon for good, they've got to come up with something better then:
Windows Server
Sharepoint
SQL Server
Exchange Server
and how MS Office/IE/Outlook integrate into all that server eco-system. The problem for Apple is they would need to hire a few 1000 employees to create a real "Enterprise" edition and by the time they got ready to present a full solution we're talking a minimum 5 years. By that time MSFT will innovate further. Maybe Apple should stick to the consumer and forget enterprise.
Who says they have to? Who says it's even necessary, given Apple's runaway success in the consumer market? No one's really focusing on Apple in the enterprise. The industry at large is focused on Apple's moves in the consumer sector. It's where all the glamour is, and certainly all the opportunity for making a mark with truly exciting tech. As consumers we can't wait to GET OUT of the office and go home to our Macs and other Apple products. I'm hardly excited about email servers and locked-down versions of XP running IE 6.
I doubt Apple wants to kill MSFT for good. MS makes a great foil and does Apple all sorts of unintended favours in terms of image. Apple specializes in the consumer sector, yes. They don't attempt to completely straddle both consumer and enterprise sectors and then end up looking inept. It's all about what happens when the user arrives home from work or is outside the stifling corporate environment. Apple offers that "glass of ice-water to someone in hell." Very true.
Seems to be working out great. Apple is in no rush to get into the enterprise, but seems to instead adopt a relaxed, back-door approach, relying on users to attempt to take Macs and iPhones into the workplace themselves at their own pace. Penetration via users, not IT departments. It's a novel approach, and is perfect if you simply want to test the waters. A consumer-oriented approach to an enterprise challenge. And Apple is in no rush, preferring to maintain the focus on the consumer sector and making unheard-of profit in the process, commanding the lion's share of attention not only in the tech industry, but from the consumer at large.
There's no pressing need at all to make a big push into the enterprise and that's why we haven't seen one from Apple. Consumers don't really seem to care, either. We're looking forward to tablets, iPhones, etc. We're not really up in arms over Apple not penetrating the workplace. If it happens, fine. If it doesn't, you won't hear anyone say boo.