Theoretical low for 30 year Fixed Rate Mortgage?

I’ve recently watched mortgage rate drop from 6.25 to 5.5. Due to current economic conditions, it looks like it’s possible for mortgage rates to continue dropping. However, I don’t know that it’s possible or likely that the rates can fall much more than 5.5% on a 30 year fixed rate. Anyone know the likely hood [...] http://bit.ly/lDI06h