All good answers. What I will add to that is that "re-establishing credit" usually means having a minimum of 3 lines of credit open for at least 12 months - preferrably 1 of those with at least a 24 month history AND ALSO record of some sort of housing payment. And there can be no late payments or collections in the last 12 months.
Lenders are looking to see that your credit problems are in the past and that you've been on the straight and narrow since then. i.e. it was a one time circumstance and not a recurring issue going forward that jeopardizes their chances of getting paid.
Sounds like the best course of action is just to put some time between you and the foreclosure and prepare for the future. If May of 2013 the earliest you can get approved, then start talking to a lender now. We can look at your credit now, identify any areas of concern, and make sure to put you in the best position come spring time to get that loan.