In theory it's possible, yeah. The game already has stats for pretty much everything, and in most cases you could probably draw some parallels between the stats and strategy used (stuff like x credits spent on tactical buildings across x planets of the player's empire, slow ship progression = turtler). But then it's not so much a learning AI as an adaptable one, and one that's easy to exploit (win a game by turtling, and know that the AI in the next game will go with a rush to try and get you before you get defenses up).
A real "learning" AI would have to make these decisions during a game.. and that's a whole other ballgame
End of Annatar11's quote
as always you have a point here. however, consider that I mean after a couple of games, not after a single one. any decent human would adapt to a player that has used a very similar set of strategies to beat him. if he does change them all of a sudden then I guess a human would be just a startled as a learning ai. the key of course is to relate it to what is going on in the current game, f.ex. via scouting. remember, a realistic ai is not the same as a perfect, or infallible ai. playing humans is often fun, because they do crazy things, unexpected stuff that sometimes failes, but surprises you nonetheless.
so while there has to be some learning and adapting during the game, I stil think that a few parameters between games would be good. depending on how deep the diplomacy changes in expansion 2 will be, it would even be interestin to establish a faction memory that remembers your trustworthyness in past games. betrayed those sect of cerebri before? hey, they might be a lot less willing to cooperate with you now.