Check the power adapter. 175W = Falcon 150W = Jasper.

Built in 256mb?

You have a Jasper.

There's a new one coming out, but that's later 2009.

http://beta.ivancover.com/wiki/index.php/Xbox_360_Revisions#Valhalla

I haven't the slightest clue. But judging by the PS2 Slim at around the 4 year mark, we're closing in on the 360's 4 year anniversary, it's possible.

Jasper is a great revision. Congrats. Personally, I am holding out for a Valhalla unit to replace my POS Xenon. I don't see it as a slim model either.

I had to replace my 360 recently and got a new Arcade model (I got to keep my 20g HDD). My Jasper came with a 175 power brick. On the sticker next to the UPC code, under the UL listing logo, it has 12V rail # that should look like 12,1A. If it has a 12,1A, it's a Jasper!

i'm waiting for my warranty to run out then i am going to get either a Valhalla or jasper model.

haha...I like my Jasper a lot.  I mean, I don't notice too much difference, since mine before was a newer model (not Jasper tho) so it was already quiet, etc, but I have played 6+ hours at a time non-stop and my system doesn't freeze, which is a nice change.  It also remains very cool.  I am happy.  I thank the Official Xbox Magazine for having an article on the Jasper model, otherwise I wouldn't have known to look for it.  I love my 360!!!

My one is playing up at the minute so just wondering folks.
If I buy a new one am I guaranteed to get a jasper or valhalla?
Or could I still end up getting the older model?

From what I hear, the Elite and Pro units are harder to find as Jasper, that might have changed though.  It really depends on where you buy it, and if that store has run through all of their older stock yet.  Check the barcode sticker for the Jasper information (12,1A) to be sure before you buy.  You can access the information through the boxes SKU window...