Hehe, I do believe the current gnutella has big improvements over the years-- I look into latest Gnucleus from time to time and have that feeling. But unless it has fundermental changes in the protocol it's still not comparable to the newer ones.
The stat you listed is about the absolute number of users-- but overall the percentage of P2P users using gnutella is going down. Sharing big files such as movies are getting mainstream in P2P world while usage of gnutella and the likes are going down; even kazaa, once the King of P2P, has lost its popularity.
btw, I guess your application target is not the same as mine-- I am more interested in video streamming and gnutella protocol does not appear attractive to me. Although open source guntella-based solutions such as Peercast do well in radio streamming they are not effecient enough for videos.