What are the upper limits of storage for these drives?  Also, if anybody is well versed in the tech, what's the potential for more layers, ie. more space and capabilities?

I know that the drive is 12X and the developers use DVD-9's...

Thats the only thing at the top of my head.

I believe the upper limit is 9 gigabytes, and Microsoft uses something like 2.2 gb for anti-piracy measures.

So the disc are SS/DL...this should mean that they can expand the disc to DS/DL...it's a cost issue, but if the tech starts gettign cheap enough, it will prevent us from having to load 2 disc...basically, 18GB, with 3 for DRM and 15GB for software.

^ Not true.

DVD5 = 4.7GB

DVD9 = 7.95GB

(This is the maximum amount of data that can be stored on either single layer or dual layer, there is no tripple layer etc).

An Xbox 360 DVD uses 7.29GB TOTAL.

Of this, just under 500MB is used in the "video partition" (this is what is loaded when you insert the Xbox 360 DVD into a dvd player etc, a small video loads saying not for use in a DVD player etc.)

Actual space available for game data is just over....

6.8GB

There is some random padding before the game data partition, but this can be a matter of a few mb up to multiple GB, depending on how much space is needed for game data.

 Its not new tech tho. The things you talk of are called "flippers" informally, they used to be used for "box sets" of DVD video releases years ago but aren't very common these days...

Expensive to produce, people don't like them...they are just really horrible. No room for artwork...etc.

(The bit about 2.2GB used for DRM is complete bollox, no offense) :)

The Xbox 360 has a 12x dual-layer DVD-ROM.  But like you said, flipping isn't much better an option, especially if it's not cheaper to produce.  I'm jsut wondering about the upper limits of  the DVD tech, and given that Toshiba is out of the HD arena, might they seek to squeeze a few more years of life out of the current tech.

http://www.xbox.com/en-AU/support/xbox360/manuals/xbox360specs.htm