Reports from AppleInsider and other sources indicate that the next Tiger update, ten-four-ten (sounds like a CB radio code) will be seeding to developers as early as next week. As Erica noted back in March, there's been some question of the exact naming for this update (10.4.9a? 10.4.9 SP1?) and it seems like 10.4.10 is the plan.
With Leopard's ship date in the autumn, some final patches to the current big cat are certainly in order. At my office we're still waiting for a fix on longstanding issues with WPA2 authentication/Proxim wireless access points on the MacBooks/MBPs... perhaps this update will be the one that clears those nagging problems.