Having had a quick read through some Wasps forums, it seems pretty clear most of their fans aren't keen on the idea. There's talk about attendances dropping from an average of 7,000 at Wycombe, to 4,000 at the Ricoh. 4,000! To put this in perspective, even if every fan who currently goes to Cov RFC switched allegiences to Wasps (they won't), that would still only get them 1,500 more fans.
Something else that popped out at me. Wasps are clearly in negotiation with more than one stadium. It suits their management just fine to have everyone believe that there's a prospect of a deal at the Ricoh, it's a useful chip in the talks with other stadiums. Similarly, it puts pressure on SISU to come to the table with ACL, which is in ACL's interest too. The only people this doesn't suit is are the fans of both clubs (and Cov RFC) - who are being treated with utter disrespect by all of the parties involved.