PC Gamer is publishing a series of articles on ME3. The three articles so far (the top three links) are on returning characters, love interests, and how enemy combat will change. They contain some minor spoilers. The largest spoiler is an enemy type that will be showing up, in the "tactical targeting" article. One of the article titles does directly spoil a returning character (though if you didn't see it coming, you're either an idiot or have payed no attention to fan response).
Overall, these articles are short and pretty slim on details. Actually, I find the Bioware people (person?) giving these interviews to be rather repellent. They are probably largely responsible for my negative view of the game so far. That said, these three articles have increased my interest a bit. (/crotchety)