http://www.trimslice.com/

Looks interesting, I've been after an ARM desktop for a while. The Beagleboard looked a bit enthusiast for what I wanted but this should be much more consumer friendly. The supposed 3W average consumption makes even the most low-powered x86 product look like it's hugely inefficient.
It'll succeed or fail on it's software but it sounds like they realize this and are trying to ensure it's as Linux friendly as possible. Although I don't have much experience of Android I can still imagine something like this being used as an Android server running an iTunes-like product to integrate the software ecosystem better. Having a backbone of Android along the entire product delivery line would also give a proper third choice to Windows and Apple.
Plenty of Google apps could benefit with local and cloud-based hosting to give that extra level of security. If you give consumers a box and tell them to plug it into their network so a server becomes more like a gaming console, it could allow much easier delivery of a multitude of IP-based services (video, voice, apps etc.)

There are other Tegra 2 products coming through and it'll be interesting to see how far Tegra 3 advances the line in terms of computing and video performance when or if it's available.

I'm unfortunately addicted to MS Windows and Office.

They they will soon be supporting ARM... and ARM is certainly likely to grow more muscles with each passing quarter. I am looking forward to this.

I've also been looking into ARM lately. As an everyday Linux user (Ubuntu), fortunately I wouldn't suffer much (if any) from switching to ARM, as Ubuntu runs on (some of) these devices as well.

I've also noticed the Trim-Slice, but what turned me away from it was its hardware accelerated video playback support - which is absolutely necessary for an ARM system to play back most video - only supports H.264 Main Profile (http://en.wikipedia.org/wiki/Tegra_2#Tegra_2_series) which won't cut it for most HD content (and indeed most H.264 content). But if you don't watch video then this of course won't matter at all.

There is another company that does ARM computers with Linux, they're called Genesi. Their products are based on the Freescale i.MX51 - and soon i.MX53 - platform, which is a single core ARM Cortex A8 clocked at 800 MHz and 1.2 GHz respectively. It's too bad Freescale hasn't released their Cortex A9-based platform yet, as I think the step up from 1.2 GHz A8 to 2x1 GHz A9 will be more than noticable (the A9 is out-of-order vs the A8 in-order architecture, among other things).
The cool thing about the Efika MX products - as they're called - is that the newer i.MX53-based Smarttop (Trim-Slice equivalent) and 10" Netbook will support H.264 High Profile 1080p decode. When software support is ready. Which it's not as of this writing.