I think it's about time that AviSynth moved off an 8 year old platform, so I have ported AviSynth 2.6 to VC++ 8 Express. This makes it possible for you to compile and contribute to AviSynth 2.6 with Microsofts free Express Edition. It might also fix some of the bad compiler issues Ian has spent so much time tracking down. If nobody have any serious objections, I'll commit the code to the 2.6 branch.
I didn't have to, and even the pro version needs an updated PSDK as soon as you install it. VC Express does come with basic header files, but I'm not sure if it's missing libraries like openMP.
Seamless, as far as I can tell, except that once in a while you have to substitute the VC6 or 7 ml.exe while assembling, or disable for loop conformance (as sh0dan mentions). For the most part every plugin I've loaded has compiled without errors on the new one. Oh, and DXSDK isn't required at all anymore (unless you're building MPC or something), DS is all in PSDK, although the version of PSDK that comes with 2005Pro is so dated that it doesn't include DirectShow at all.
Express doesn't include the resource editor but that doesn't mean you can't import from VC6/7. Odd about the other one though. (Avery has amazingly informative blogs about VS.)
@sh0dan: - By all means checkin any syntax polishing you have worked on. Getting the source syntax cross compatible is a very important first step. My thoughts for doing a platform change would be to do it as a null functionality change so we can do A - B cross checking. Something like develope 2.6.0 under VC6, with near as possible 2005Exp compatible syntax. Do 2.6.1 as a bug fix release + reworking of things like the *.ASM's and the try/catch(...)'s that will choke in 2005Exp. Then do 2.6.2 as an Identical 2005Exp release of 2.6.1 i.e. no new features just pure base translation.