Clearly, I've got to stop sleeping, if I'm ever to stop waking up to such amazing news...but anyway, in no particular order, at least not until the end of the list...

1. AT&T has a strong relationship with Apple thanks to the iPhone. AT&T also co-brands high-speed internet service with Yahoo!. (It's really difficult to be grammatically or typographically elegant with a brand name that ends in an exclamation point.) What happens to those relationships if Microsoft buys Yahoo!?
2. Speaking of branding, what happens to the Yahoo! brand? Will Microsoft keep it unchanged? Will it become something like "Yahoo! Powered by Microsoft" or "Yahoo! from Microsoft" or "Microsoft Yahoo!?" Or might Microsoft actually consider morphing or killing the Yahoo! brand altogether?
3. A separate but related and perhaps more meaningful question to more people - what happens to the multitude of e-mail addresses that end in ".msn.com" and ".yahoo.com?"
4. What happens to the media industry alliances that help to determine which content is available on which portal? Or to Zune users?
5. Will Yahoo!-originated content be repurposed for MSNBC, the Microsoft-NBC Universal alliance?
6. As long as we're musing about content, what the heck happens when Microsoft's Plays for Sure "digital rights management" scheme comes up against Yahoo!'s, er, slightly more open approach to such things?
7. Will the combination of forces result in any new online "personal productivity" services that can compete vigorously against Google, Zoho, and other alternatives to Microsoft Office - without cannibalizing Microsoft's cash cow?
8. If there are advertisers playing Microsoft and Yahoo! off against one another, what will those companies do now?
9. Just how much bloodletting will be required to achieve the "economies of scale" and "operational efficiencies" Microsoft cites as reasons why Yahoo! should love and accept Microsoft's buy-out offer?
10. Ultimately, the real fundamental question: which company's worldview will dominate? Because that's as likely as anything to determine how this deal goes forward - if it does - and what happens if it doesn't.

Sometimes, asking the right questions is essential to figuring out the right answers. Let's hope the folks at Microsoft and Yahoo! are asking the right questions, and that we who are likely to be affected get to learn some credible answers soon.

(On another subject entirely - if you or any of your colleagues have any interest in service-oriented architectures or SOAs, please go to http://www.aberdeen.com/survey/soaperform/ and take the 15-minute survey on SOA performance. You'll get some free Aberdeen Group research that I've written and am writing, and I'll get to include your input - anonymously, of course, unless you choose otherwise. Thanks!)