Kernel 3 needed.
Here's an explanation :
Recently, stock ICS has started to have camera working, including video recording, photo capture...
On the other hand, Sense ICS ROM can't get camera working.
This is the same OS version, for sure.
But stock ICS is built from source.
Sense ICS is built by HTC. We don't have the source code, neither of the OS, neither of the kernel.
Stock ICS kernel uses wrapper that makes old Gingerbread libraries working.
This needs to be done when modifying kernel source.
As we can't edit Sense kernel source, that won't be possible to have camera working until 3.0 kernel. For now stock ICS rom are using 2.6 kernel.
I hope this will answer questions about camera