I'll be the first to suggest it...
But Apple should think about making a play. 'Why?' you scream out (probably only thinking of Apple as a consumer business)? Well, let me explain:
1. Apple has an array of server products Xserve, XSAN, etc.
2. Apple has slowly been improving and extending its offerings to businesses. Traditionally focussed at smaller businesses, the server products are now supporting ever features that will appeal to larger organisations - e.g. better virtualisation support, system management software.
3. Apple is a 'sexy' company with a lot of marketing capital behind it. Compare it with Sun who have a lot of developer mind-share (from Java) and clearly lots of clever brains (ZFS). Sun could benefit from the Apple image and Apple could benefit from inheriting the smart technologies at Sun.
4. Apple and Sun have a good relationship - look at ZFS, commitment to support Java, etc.
5. Sun does have mature experience in mobile systems learnt from JavaME. Their strategy may not have been perfect but there is still some neat lessons Apple could benefit from.
6. We can see that the iPhone is supporting more and more corporate technologies (remote deactivate, central configuration and support for Exchange Push). This, coupled with increased demand of Mac workstations from business users is creating interest from IT departments to consider Macs more fairly in comparison to traditional server technologies (Windows).
Making a play for Sun, Apple would inherit some clever people who can improve the core OS X and add clever new technologies. They could also gain instant credibility in dealing with businesses - a direction they're already slowly moving towards.
Oh, and Apple has over $16bn in the bank and from past executive comments, acquisitions are likely when the right opportunities come up.