AFAIK, No one but @sairon is working on the YAC wallet (awesome work with the coin control feature btw).
Behind adding checkpoints (on the @Windmaster fork), nothing else has been done on the client since the official release.
Umm, I think there are somewhat more changes in my fork than just adding checkpoints.. See if you can get the original official release to compile on Windows, and if you succeed (without replacing all the scrypt-jane library source with a newer version altogether), also keep score on how many times you see unchanged "Novacoin" and "NVC" text plastered all over the original client. Or try to get an estimate of the network hash rate out of the original client, or find out the current N or Nfactor without looking up the time-vs-N table I generated (and everyone else reposted in various places).
I forgot about all the new API calls, you put a nice amount of work on the original client. My apologies.