Initial testing with Team Xtender's "HD Connect" has revealed full compatability with all tested homebrew applications, no modifications required. Even more interesting, testing with HDLoader has revealed that what were previously believed to be incompatability issues with hardware or the PS2SDK are actually caused by an oversight in the design of HDLoader itself! Rest assured that a patch will be released here soon that allows the use of HDLoader on PsTwo consoles with Team Xtender's IDE HD Connect kit!
Team Xtender Has announced that they are now taking pre-orders for the HD-Connect Kit! View this news post on their site for more info.