I've just uploaded version 3 of libpcre. I've put it in a new package, libpcre3, and given it a new soname. I'm not sure if this was strictly necessary or not: the upstream documentation doesn't mention binary compatibility with the old version, probably because older versions weren't intended to be built as shared libraries at all.
I intend to stop maintaining libpcre1 (not that I've touched it in the last year as it is) and think it should be removed from debian; I will continue to fix any bugs in libpcre2 but would like to see as much as possible migrating to using libpcre3 instead; this should just be a recompile for most things. I'll package a new version of exim tomorrow which will be linked against libpcre3. Once this is uploaded, I'll request for libpcre3 to be made standard priority and libpcre2, currently standard, to be made optional. Please Cc me on any replies as I don't normally read this list.