My Frankenstein of a Media Center is still acting up in it’s new home so I’ve ordered a new Dell XPS 420 with dual CableCard tuners, Bluetooth, and a media card reader to replace the MCE2005 and my desktop. Sadly, the rest of Dell’s available upgrades are complete rip-offs — they actually have the nerve to charge more for some of their monitors bundled with a system than they would sell for separately! And then there’s the $150 to upgrade from Vista Premium to Ultimate… Hopefully I can get my current license to transfer, tho for the life of me I can’t remember WTF is so great about Ultimate.
Some searching on Fatwallet netted an MPP coupon for 10% off, a trick to get 4% off for using a Dell Preferred Account, and some other deal for 4% off on top of the existing $100 off and free shipping promos. All told it rang up to just under $1,150. Feels like a lot but I’m gaining two cores, CableCard, and slightly better video…
The DPA has a 0% interest until 2009 promo so that gives me a while to figure out how to pay it off. Selling the Dimension 9200 (XPS 410) and the Subaru 2.0L shortblock in my garage ought to get me past the halfway mark.

You might check out DealTaker.com for coupons as well.
There are many sites that post Dell coupon codes and promotional links. The thing about Dell is that if you don’t like the price today, you very likely can find an even better deal tomorrow.
In my hunt for the absolute best price I came across a promo link somewhere for $500 off an XPS 420 w/ a 4-year warranty and 18-month anti-virus package, the total cost I think was around $100 more than the promos I used. To me a multi-year warranty on a PC isn’t worth anything but for someone that expects to keep their PC for 3-4 years it would be a heck of a deal.
Just for reference, I “saved” $234.85 beyond the promotions listed on the Dell site. Based on my past experiences buying from Dell I probably left ~$100 on the table by not checking the coupon sites and Fatwallet daily for 2-3 weeks.