IMHO, if you came out with something like 4U/5Kw/3 or 4 board version in the 20-25TH range you'd make a killing.  I think that would still keep the home miner in the game as basically anyone with 5 SP20's running today should/would be able to convert over to this. As with the SP30/31/35 the rack mount form factor would be great for those of us in a datacenter setting.