Yeah the Xbox linux scene hasn’t really seen much activity since 2007, except x-dsl.
If you want I can try to get in contact with the author.
btw how is Cromwell ‘painful’ to compile?
By “painful”, I mean: It didn’t 
It seems the latest versions of GCC 4.x throw more warnings now, and the Makefile explicitly treats warnings as errors, so I first removed this from the makefile, after that, it still failed to compile, so I sort of lost interest at that point, as I had other things to work on instead.
So, I did flash Cromwell 2.4.0 to my X3 and it boots Linux from the “F” partition… next step I’ll probably dedicate an entire disk to Linux, (probably X-DSL as you mentioned), and see if I can use it to build Haiku. Xebian is so old now (based on Sarge?) that trying to execute an apt-get dist-upgrade is a disaster that ends in tears (I tried two different times, with different listings in sources.list hoping to make it work incrementally).
Once I get Haiku compiling, I’ll squeeze it onto a partition and set about seeing what it will take to bootstrap it.
Just to let you know, you don’t need to flash cromwell BIOS to run modded code, you can softmod using the “hotswap” method or by using a specially crafted save to modify the HDD. You run it from an alternative xbox dash that allows for booting without special partitions. You can also flash the bios with the xdk dash http://www.xboxisozone.com/downloads/344/.html and here is a dev kit for those curious to mess with it http://www.xboxisozone.com/downloads/362/.html. You could probably compile the source for haiku using that or the OPENXDK if you don’t mind the missing stuff http://sourceforge.net/projects/openxdk/. The added benefit of the debug dash is to “debug” your code, and you can play games using it as well, but you can also use Unleashx or XBMC xbox version here http://www.xboxisozone.com/downloads/321/.html I also uploaded a raw hd image to xboxisozone that tells how to use haiku under xdsl’s Qemu.
Haiku is MIT for a reason. You should be able to do almost whatever you want and the community should follow the spirit by encouraging it…so if someone wants to port Haiku to their refrigerator (wasn’t there BeIA for that?) either for a learning experience or because it may be useful: great!