I'll be the first to admit that I don't know much about poker, but I do know something about software development. As I understand it, the cheating was done by an in-house programmer (albeit a consultant.) The company has to have security measures in place not just on the players, but also on the development team (code reviews, pair programming, etc) to make sure that the code base is secure. If a programmer is sufficiently skilled and has free access to the code base, this kind of problem is definitely possible.
I think if anything this will be good for online poker in general, because attention will be given to an issue where, at least at Absolute, security was lacking.
If they have truly addressed the problem then playing there is no more risky than playing anywhere else. Of course thats easy for me to say, as I don't have money there.