I was a pretty huge fan of Alias when it first started, but then it got really bad, really fast. It focused way too much on this dumb and convoluted mythology stuff (any mention of Rambaldi still makes me shudder) and lost all the fun of the first season. So far, Covert Affairs on USA seems to be trying to just be that fun Alias of the first season.
For one thing, it's a much simpler show. Annie Walker, our main character played pretty winningly by Piper Perabo, is a rookie CIA field agent with a gift for languages. She works out of the CIA headquarters in Langley, VA, so there's no question of who she's really working for. Her missions usually don't have elaborate covers and disguises and wigs and she's not really supposed to be getting involved in much action (though of course she does, because something always goes wrong). There is some overarching storyline with an ex-boyfriend of hers that the CIA seems to be tracking and using Annie to get to, but they haven't gotten much into that yet and it likely won't involve a big red ball (sorry if you've never watched Alias and don't know what I'm talking about).
Annie is supported by her handler, Auggie Anderson, a former field operative who was blinded in Iraq and now is running tech ops at Langley. He's played by Christopher Gorham, who's probably the most charming he's ever been. I think it's because for once he's not playing the earnest, bumbling geek...he's still a tech nerd but Auggie is actually kind of a ladies' man. The blindness part is kind of interesting, there's all sorts of crazy Braille devices and stuff to help him run the computers. I guess as this is a TV show a romance with him and Annie is inevitable but I'd rather they not go there...I think Annie and Auggie have more of a buddy chemistry.
Other characters include married couple Joan and Arthur Campbell (Kari Matchett and Peter "Eyebrows" Gallagher) as Annie's boss and some other CIA head, respectively, and Anne Dudek as Annie's sister, Danielle, who doesn't know about her job. Sendhil Ramamurthy (eek, Mohinder from Heroes) pops up as another agent, but I don't really know what his deal is except that Joan doesn't like him.
Overall, I would say this is definitely a "summer" show. It's pretty fun and light and a lot of the cast is likable. It doesn't take the risks that Alias did but because of that it probably won't crash and burn either. I'm going to keep watching it for now, but I can see myself eventually getting bored of it...