Just talk to me loan officer, he told me that:

For Freddie Mac, it's not number of loans, it's number of properties per each individual. Fannie Mae is fine with 10 properties like usual. If Fannie Mae wants to change guideline, it will give enough time period before their actual execution. For example, it will say "starting from October 1, 2008, ...", no, it's not going to immediately affect us right now.

My advice, if you can get low priced auction or REO, do it quickly now with Fannie Mae. With REO pricing as low as 100K or lower, you can grab 3, 4 of them all at once.

My loan officer says that don't worry for the long term, Freddie Mac/Fannie Mae will relax guidelines as easily as they tighten guidelines.