Private label Gmail

I've heard again and again...

"I'd love to use Gmail for my company mail and can POP mail *IN* but can't send mail with my company domain *OUT*. I'd pay to be able to do this!"

So this raises the following questions for me:

Some questions:

1. What size would the market be for this in the A) personal B) small/home-office and C) medium/large corporate spaces? Would individuals and companies really ditch Outlook/Exchange?
2. Would this 'private label' version of Gmail still show ads?
3. Would it cost money? If so, how much, and if not, would ads be the only revenue stream?
4. When can we expect to see this new offering?

My guesses:

1. A) Not large. Individuals with their own domains probably want the extra features that geek-mail-software offers, or the integration with Palm and such that Outlook offers.
   B) Pretty substantial. Folks in this position may travel a bunch and really relish being able to check and send (branded) e-mail from any computer. Also, they're not likely to have MS Exchange set up.
   C) Questionable. Such firms likely are too entrenched in an Exchange environment and have security / privacy concerns that have already been QA'd against Outlook.
2. By default, yes, but you could pay (extra) to get rid of them.
3. I anticipate a three tier set of offerings: Free (current version), Private Domains, and Enterprise, with only the latter having a fee based upon number of seats. No idea of the cost per seat, though.
4. September 12, 2005 or April 1, 2006

Your thoughts?