As of late have been messing a lot with XBMC.
Migrating to a new virtualized MySQL server for a centralized / networked library from its previous location, with MUCH improved performance!
Trying to get wireless to work, few functionality with Remotes, in particular with subtitles features, and Apple's AirPlay protocol.
Evaluating RASPbmc, OpenElec, XBMCbuntu, and considering PLEX on my Acer Revo and Raspberry Pi devices.
Mixed results thus far...

Finally got my slice of Raspberry Pi

Pretty cool and as promised invoiced / shipped affordably.It is indeed very very small the packaging could quite simply be mistaken for a box of playing cards.It does indeed ship w/ no manual/instructions of any kinda just this PCB.Powered via a std microUSB cable.I also tried to boot via USB stick into XBMCbuntu but was unable.There is a SD housing that does seem bootable.Had initial issues loading XBMC until I realized XBMCbuntu was not just supported. OpenElec has announced support for their port of XBMC but has yet released an image to general population. Found Raspbmc variant and it did boot albeit a string of Linux stuff I didn't understand to know if some errors were important or not.  Unable to get any audio no matter if changing to analog / hdmi or any other combination I tried. (In fairness didn't have the opportunity to test fully).The initial image from raspbmc would not fully install and found a beta image via an obscure FB post on their page.  Subsequently they have a new RC2 out I will endeavor to try.The performance left some to be desired but the Raspberry Pi is new and so are these ports so I'm hopefully it really can stand up to delivering 1080p video and its not a HW limitation. Also I the NIC on the Raspberry PI is only 10/100 so concern there w/ large file sizes / bandwidth but I think I had media center connected to a 10/100 switch before w/o issue. 

I do think its a bit odd how some of the ports are flush w/ the board and some aren't and also of varying degrees to each other. And the ports are all over so thicker cables and add leverage to the board pulling it in different directions since there is no weight to it. I'm not a developer but the tinkering aspects still intrigue me but ultimately if this can be a legit stand up media center I'll be very pleased...otherwise I have no immediate ideas on how I will personally put it to use quite yet, since I'm a Linux novice that seems like the most applicable way to go to have the least overhead on something such as this.

UPDATE: RC2 is drastic improvement, after being provided to gen pop. I think possibly still some errors but silent/unattended install and much much faster than previous.  Sound working out of the box now, even DTS audio.  Still some choppiness w/ playback of 1080p hopefully further refinement will help and not HW. Looking much more promising though. Good job Raspbmc.

Going to try to develop a case. Thinking HDPE foam, plexiglass/plastic, machined aluminum or LEGOs. 

UPDATE 2: RC3 Released 6.20.2012One click download / installer disk creation
Instant boot load. Good feedback GUI. Silent / unattended install. Plug / play out of box. 1080p improved as promised no lag thus far. Couldn't recognize my usb wifi dongle that openelec did, that would be terrific. Outstanding work, much thanks.

UPDATE 3: Frustrated as my main machine is running base Eden11 while the Raspberry Pi is running a nightly build variant and thus uses a new schema to the centralized mySQL media library for those whom have it setup. Thus to utilize the mySQL library all connected devices MUST be on the same code level. Frustrated how XBMC is handling these database schema changes and how flawed the migration path is.

Nice form factor / size. Several extra features u can't easily get w/ comparable products.
I've had the trackball media center themed remotes and the balls are too loose that it errantly affects cursor movement.
Trackpad alleviates that.
L and R mouse buttons. Yes thanks.
Full Function Keys to F12 which helps get into BIOS and other system.
Embedded sensor housing? Nice touch.
Rechargable by standard USB port ? why thank you.
MULTI TOUCH trackpad? Really?? thanks.
Even a red laser pointer albeit not sure why, except maybe if you want to torment a pet cat? It works so I'll not complain of it.
For newest media centers and when you want to TYPE to search or browse this is a great complement to have for those wanting for Media Centers or just a handy portable keyboard to have around in a pinch for the price.