Unfortunately I'm going to have to agree with Punisher and Ghost- UT3 isn't doing so well.  UT99 is actually doing better than UT3 at least right now.  UT99 has more players in every game type than UT3.  If you compare UT99 with UT2004 that's a different story.  There are a lot of new players coming into UT3 but they never stay.  We've had about 13,000 players come on our servers the past year but only about 10% of them stay to play another game, 1% of them stay to play for at least a month or more.  The competitive scene in UT99 is much, much better than UT3.  The sniper side of UT3 was pretty strong in the beginning but has died off.  The mod scene in UT3 is bad. etc...

I thought UT99 was dying before I left for UT3 but honestly UT3 is in a pretty bad state right now.  UT3 isn't seeing much growth at all.  Hopefully the new patch and expansion pack will help UT3 out a little bit :).  It'll probably be awhile for people to have PCs to play UT3 as well.  I wouldn't worry about UT99 though- I don't see it dying off anytime soon.