I would say absolutely, if only to get yourself re-acclimated back to the world in a way that just reading the wiki doesn't match. Especially if they are going to be bringing back relatively obscure characters from those games to play another role.
DA2 is kind of a slog, and it suffers from an ending that, while not quite as stupid as ME3, still feels extremely phoned in as compared to DA:O, which could have many, many outcomes depending on how you made decisions, your char, etc. DA2, it all kind of gets washed away in an obvious copout/reset to prepare for 3. It still has some awesome moments, however, that merit a quick revisit to get mentally ready for Inquisition.