I'm not in it but I know a lot about it.
Basically from what I understand you apply to the program and typically you need pretty pretty good stats (especially if you are in Texas) or a 4.0 while at UT. The program is quite rigorous and you must maintain a certain GPA requirement to stay in. Classes are very small and there is heavy interaction between the students and professors, especially with the required research.
I feel it is a damn good program for the money you pay (#7 in the Nation i believe) and most of the graduating students I know of have received offers from Google and Microsoft.
http://academics.cs.utexas.edu/under...out/index.html
see there for more info