Apparently some vendors have reviewed android and also fixed
the ashmem issue in 2.2.1 (along with adb and zygote).
However, I got the first reports for KillingInTheNameOf
working on 2.1 devices. So I made it available
here.
It was really my favorite and I hoped it would become
the Gingerbreak, but 2.3 is not using
ashmem for system properties. Thats life :)
[Update:] it seems like the property space has become
the new playground for breaking froyo devices since this post,
as the ashmem implementation has some shortcomings if
it comes to properly protecting the property space :-)
The security of the whole system relies on the property
space due to ro.secure and other properties.
However for Gingerbread, the property implementation has been
redesigned AFAIK.
Also check out this link for another method of exploiting
ashmem which apparently also works on 2.2.1 devices.
My Gingerbreak works, but I wont release it before a couple
of devices are in the wild so the issue is not fixed before
it can become useful.