Following on from the release of the Xperia arc system files, one of the devs (TripNRaVeR) over at xda-developers has ported over this arc ROM to the Xperia X10. This new custom ROM is based on Android Gingerbread (v2.3.1) and includes apps from the Xperia arc including Timescape and the Mediascape widget.
The release is at a very early stage, so there are a number of bugs including no sound output (for incoming calls). However, it’s impressive the number of things that do work including the network, data, wi-fi, Bluetooth and GPS. It also includes the default Gingerbread keyboard. For more information on the ‘TripNArc’ ROM click here.