Yes, it does in fact mean "tits and ass", but it rarely is referring to the anatomy of just one female. It is used more in a descriptive generality... usually used to characterize a particular genre of entertainment, e.g. movies, TV, pop music, etc. It is often used pejoratively.
Wow, MTV used to be so cool. Now, it's all rappers and T and A.
Have you seen the amount of T and A that has crept into video games these days?
Journalistic abbreviation for 'tits-and-ass,' used when the complete phrase would be out of character for the piece.
The much-hyped, big-budget Super Bowl commercials always offer something to gag over - the Pepsi spots featuring the teen bimbo pop singer of the moment; the beer ads that pretend to make fun of sexist t-and-a beer ads by, well, showing lots of t-and-a.