Sean,
Take a look at this thread.  It is a posting I made a few weeks ago.
As of last Sunday the phone was still available in store.

http://groups-beta.google.com/group/alt.cellular.cingular/browse_thread/thread/f
5fc746f784e19ae/23381e38e57052f0#23381e38e57052f0

SeanD Wrote:

The MPX220 is still available through private non corporate stores
there are plenty on line to choose from

Thanks guys, I saw  a really sweet deal on the Cingular site just
before they pulled it. Guess I should have jumped at the chance.
Sean

Here is another thread that talks about it:
http://groups-beta.google.com/group/alt.cellular.cingular/browse_thread/thread/1
663d5062858373c/7a796dc85b56908b?q=MPx220+discontinued+-+more+info%3F

It had an issue and Cingular dropped it from its offerings. Moto was to fix
some firmware issues and they were supposed to adopt it back, though have
not heard of them doing so yet.   Some of the stores still have back stock
on the item. Though if you are going to move from Cingular to Cingular and
just change your phone, the price of the unit is too much.  Its only worth
it if you are going to get the discount with the new Service offering.

I think Amazon had it for $99 if you are looking for new Service.
http://www.amazon.com/exec/obidos/tg/detail/-/B0006I2HN4/103-2830900-8851829