I didn't see any comments about old/new-style module building, so here is a short explaination.
The old-style, requires modules to have a number of files and pretty much assumes it is a CMOD. If developers want's to distribute a pike-only module, they still have to provide all kinds of stuff to make the build system happy. The old-style compilation also drags in alot of includes created when Pike was compiled, with defines that could be invalid for the machine that is building the module.
So, to work around those problems and simplify module building quite a bit (in most cases), we decided to introduce the new-style module building. This new way of building modules for Pike basically gives the developer the posibility to get CFLAGS, which is really all you need to compile external modules, by running "pike -x cflags".
If you need to test for other features to ensure that your module runs, you should really write your own configure tests and use the results of those to determine if your module can be compiled or not.
There was talk of extracting a bunch of tests from Pike's configure suite to a library which modules can use to test for features. This would be a nice to have feature, since Pike's configure has a ton of workarounds for various situations and strange OS. However, this feature is still to be implemented.
In the end, it should be alot easier to write modules that compiles most of the time. If you want to write a robust module, that checks for prerequisites properly you will probably have to do some more work now, but the end result should be far better and more reliable that it was before.