Remember that Sony is a monster of a company, and they sell gobs of hardware as well. It's entirely likely that their promise of not engaging the downconversion flag on Sony titles could be rescinded at any time to "combat piracy" - in other words, if they think that by doing so they could sell more SXRD TVs. And the result would be the same - those with older TVs would be back to square one.

They might wait a bit to ensure market penetration and be sure that people are locked in to their product, but there's no doubt they'll do it. And with the age of Digital-only TV only 3 years away, they probably wouldn't feel overly obligated to justify the decision.