That's the root of all problems. As long as we need an old kernel to support proprietary blobs to run our hardware we will keep falling behind Debian's state of the art. One of the main problems is the phonet firmware. How long have the nitdroid people been trying to get that working?
Or have a look at the Lemote Yeeloong! This netbook was shipped with some sort of Debian Lenny but the kernel included some proprietary blobs that make a complete dist-upgrade to Squeeze impossible and Wheezy will not be an option on that device. So the lifetime of these devices will be over after the support for Squeeze will be ceased. The same will happen to a "Debian-N900" that sticks to kernel 2.6.28.
It's situations like these that make me forget my pragmatism when being stopped by proprietary software requiring people to do the same work again and again stumbling in the dark.

I see that as the only realistic way to have a system that has long-term support and is up to date. Imagine you'd be forced to use Sarge today!

The difference between us and Ubuntu is that we are in a tiny niche while Ubuntu is huge, in some aspects even bigger than Debian.
They talk to each other at eye level, we can't. So we either have to integrate or we won't participate.

Really? What's the difference? I see two of them but none of them qualifies to accept being tied to proprietary software or having to be separated from Debian's mainline:
1. Different interfaces: That's purely a userland topic. So there's no reason why mobile packages should conflict with desktop packages. It's as easy as installing another desktop environment.
2. Different performance: Mobile devices will always be weaker than desktop computers. But they are already strong enough to run most desktop applications. I still have a desktop computer that runs Debian fine but is outperformed by my N900.