s there an easy way, (or utility) that can be used to import archived email, contacts, etc from one existing gmail account to another? For example I have two domains:

webmail.abc123.com, with an addie of belliottabc123.com

and I want to migrate the data to:

webmail.abcxyz.com, to the addie of: belliottabcxyz.com

I have used all the forwarding options to send new mail over, but can't figure out if I can migrate mail, labels, etc. Any suggestions would be highly appreciated!

GMail supports IMAP so either:
(1) Go to the "Get mail from other accounts" in settings and add the imap details for Gmail and the other account, this may import all messages (it might only import new ones, I haven't tried it)
or
(2) set up GMail to download via IMAP for both accounts in a regular IMAP client (e.g. Thunderbird) and simply copy and paste emails from one account into the other in bulk (this "upload" of messages into GMail simply works, now that GMail supports IMAP). The labels won't migrate over unfortunately, but simply setting the same filters again and choosing "apply to existing conversations" should do the trick (but not for those messages you've "manually" labelled).

If I understood the question correctly, you want to import (wholesale, so to speak, and with retained posting dates and msg hierarchy) mail from one Gmail account to another Gmail account. In effect, you want to merge two Gmail accounts, or simply change/ update an account's name.

Well, Gmail's EULA terms are pretty clear on that: you are only permitted one (count it: "1") Gmail account, not multiple ones. So, no, there are no published kosher ways to do it, although there might be methods to mechanically resend archived threads in sequence with added, usually invisible, but no less indexable for that, X-header string containing the original posting RFC 822 date. Which later could be used as a search- and reordering/onscreen-rerendering term in Gmailboxes.

<< Gmail's EULA terms are pretty clear on that: you are only permitted one (count it: "1") Gmail account, not multiple ones >>

Completely inaccurate. You can have as many Gmail account as you want. The TOS only says you are not allowed to have multiple accounts to send spam. You must not "create multiple user accounts in connection with any violation of the Agreement or create user accounts by automated means or under false or fraudulent pretenses." (http://mail.google.com/mail/help/program_policies.html)

Regarding Bruce's question, use Gmail's mail fetcher to import messages:
http://mail.google.com/support/bin/answer.py?hl=en&answer=21288
while contacts can be easily imported/exported:
http://mail.google.com/support/bin/answer.py?hl=en&answer=24911

I apologize for any misinformation, but it certainly haven't been like that all the time. If one is now allowed more than one Gmail account (within Google Accounts), what is it that prevents Gmail team from implementing import/ merge (and related straightening-up) among these, which would also have eased load on their own servers somewhat?

More than one account per user means more than +6 GB per user. It's a waste of space allocation, it inflates -at least- statistics.
But I'd like to have more than one address in gmail...

Methinks the nominal 6GB+/user is a virtual figure arrived at by calculation of some (projected memory usage model of X --a variable but large number of-- users) making a divisor for current and near-future Google memory-bank capacity, not a straight memAlloc() for each an every user. If more than, say, 5%? of us does at any one time come near the limit, the model gets adjusted, VM reallocated, and Google buys some more chips at prices we mere mortals can but dream about (even though RAM nowadays is but a commodity....)

Thank-you all for your input – it will gladly be used. Thanks also for clearing up the use/mis-use multiple accounts issue. Our situation was one of a parent organization absorbing its child, and all of the email accounts needing to migrate to the new domain. After a period of time the original domain will be closed. Thanks again for everything!

For what it's worth, the IMAP method worked great for me for putting email I had from old POP accounts dating back to the 90s into my Gmail account.