Zdzihu from xda-developers has released a new custom Android 2.2 (Froyo) ROM for the Xperia X10. The release is timely considering that Sony Ericsson yesterday officially confirmed that the X10 family will not see an Android revision beyond Android 2.1 (Éclair).
The ROM is currently in Beta and can be installed through xRecovery. A hot fix has already been released that addresses wi-fi DNS and ringtone loop issues. The first beta release of the FreeX10 Froyo 2.2 custom ROM can be downloaded here.