I'm not technically a developer, but I am the head of the beta team, so I figured I'd do a diary entry to give you guys outside the beta insight into what goes on.
Before 1.9 went to beta, I was testing the alpha builds that jlf put out. The only people testing the alpha were staff members, so this made testing with multiple people much more difficult than it is now. I'd spend 30 minutes or so with each build, testing out the obvious (weapons, flag capturing, etc.), which suprisingly didn't work half the time. We had some weird bugs where flags would slide around the map if dropped, and were unable to be picked back up. We had a horrible bug where blocks would mysteriously become invisible, which caused a great delay in 1.9 moving to beta.
And we also "drew" some ASCII art on the bug list, because we got bored:

(click to enlarge)
So atleast you know we're working on important issues. We did some more but I don't want to try to screenshot it all.
Beta testing has gone extremely well. Our testers are awesome. Not only have they found seemingly every obscure bug there is to be found (having the shellshocked sound when you get grenaded play forever is by far one of the worst, nearly threw my headphones off), but they've really helped with class balancing (who knew giving the strongest class in the game the AR2 and the shotgun would be a bad thing?). We've had some intense games lately, forcing us to reinvent some of the classic SourceForts strategies and building techniques. sf_resevoir is quickly becoming my new favorite map, and will be released as a part of 1.9. It's just perfectly suited for a competitive match. The new sf_skywalk is also pretty cool, though I'm somewhat biased against it because I found myself falling off the edge to my death more often than not, due to my bunny hopping habits.
Overall, beta testing 1.9 has definitely been the most fun I've ever had with SourceForts. jlf has done an awesome job of responding to reported bugs, and listening to our ideas for gameplay changes and balancing issues, and the beta testers are doing a great job of exploiting every feature to the fullest (especially Dredge, who plays by far the cheapest Builder class

).
I'll leave you with this screenshot I took earlier today just as the match ended on sf_resevoir. I must say, it was a pretty close game.
More to come as we draw closer to release.