I finally got round to starting Fallout 3: Broken Steel last night (well, more this morning) and I finished it within about three hours (if that).
Overall, I enjoyed it. The new weapons are allright, not great but allright. The new armor and stuff is quite nice and the missions were quite fun to play through. The last one was a bit frustrating but I got through in the end. Lasted for a good hour as well, which was rather nice.
I haven't played the other expansions just yet, for the simple fact that they're £8 each on the PS Store but I'm sort of looking forward to playing them with a cautious excitement. I've heard Broken Steel is the best one and... while I enjoyed it, it was far too short and had a lot of problems. Sometimes my PIP Boy just wouldn't come up and a lot of the time the frame rate was god awful, sometimes dropping to what I presume must have been 5 - 10 FPS which is just awful.
Still, I have the option of getting my hands on the Game of the year edition which has all the expansions on it, as soon as my girlfriend finishes it.