At first glance I thought to myself, “but isn’t Google doing the same thing lately with sites like blogger and orkut?” That is, until I double-checked. While Yahoo! is in fact trying to force the move, Google (for now anyway) is simply allowing users to sign up for the services (or migrate existing accounts) to a Gmail account.
Yahoo! seems to be moving more in the direction of brick and mortar, trying to couch their dealings and services as they want rather than as the users want. While I’ll admit Google is far from perfect, they seem to want to conserve at least some level of choice for the end-user.
On the other hand Yahoo!’s minimum width seems to be for 1024×768. Google seems to go around 640×480 (like this site). My old theme was set for at least 1280×1024 I believe (well, width is what matters) and I’m still trying to figure out where it should be.
Overall, reaction to the new theme has been pretty positive. By that I mean I like it.