Did proper nouns all of a sudden become low-quality?

A small but noticeable group of SEM experts have noticed that Google's AdWords system has recently lowered the Quality Score for many of the proper nouns they buy. Forum discussion on Webmasterworld is here.

First Google opens up trademark bidding to boost otherwise flagging revenues, and now all of a sudden they're deeming proper nouns lower quality (and thus lower Quality Score) for which there was no change in landing page. This can mean one of two things IMO:

1) Google has identified a keyword sector that will bear higher CPC's and is inflicting them;
2) Someone at Google thinks proper nouns are worth more because they're, well, proper

Either way, I see hot burning coals under the feet of proper nouns, while adjectives, predicates, adverbs and conjunctions go untouched...