There's a bit of buzz about Redfin's recent site upgrade. 

Live as of last Wednesday, the upgrade has added bank-owned foreclosures and FSBO listings to their inventory display.  

The bit of the controversy comes the question of how they were able to get around the MLS co-mingling display issue; the FSBO listings are listed alongside those from the MLS.  (Ref. 4.13 in MRMLS IDX policy... "Listings obtained through IDX must be displayed separately from listings obtained from other sources...")

While no hard-fast answers jumped out from the discussions, I publicly wonder if the answer might be in their use of a display filter along with differentiated icons to "separately present" data that was obtained from other sources?  Redfin's Glen Kelman assures the community that the MLSs worked with them on the release and guided them on the approach to listing different types of inventory without violating the rules.  That's helpful, but the Curious George in me still wonders what the details are... any thoughts?

And, oh yeah, be on the lookout for auction properties which Redfin says may be added in the future.

[Video interview with Glen Kelman]