I got the distinct impression watching "The Mummy: Tomb Of The Dragon Emperor" that everyone kind of ran out of steam for the project when they found out that Rachel Weisz wouldn't be playing Evie. The rest of the main players are played by the original cast and do a sometimes excellent, sometimes half-assed job of it. The script starts off tight, and turns farcical and kind of lackluster a short way into the film. I was also disappointed that all of the SFX budget seemed to go into CGI - a good mix of subtle CGI and excellent mechanical effects was a hallmark of the other two movies.
However, everybody who wasn't in the original movies was excellent in the new one. Luke Ford plays Alex O'Connell convincingly as an O'Connell, Maria Bello did as good a job as can really be expected when you have to cut into a tight cast, and all of the HK actors and actresses (Jet Li, Michelle Yeoh) really give it their all. I almost wish it had been a handover movie, with Rick dying and Alex taking down the new mummy - that would have suited the atmosphere better.