I'm not totaly up on the VB hacking community, but I'll say this..
As with any product of this nature, the hacking community is better due to it's installed base. If UBB.classic looses market share, slowly the hacks will slow down as well. There will be fewer new people coming into the market, fewer people asking for hacks, fewer people making them. As hacks become slower in coming, the installed base may loose even more, thus a snowball effect.