I always say the same thing in regards to plasmas:
You don't need to WORRY about burn-in, you just need to be aware of the possibility.
It is extremely easy to avoid, and almost requires an effort on the part of the owner to get it.
So, if you aren't blindly negligent, but instead switch from 2.35 programming, to 16:9 programming, to 4:3 programming and back and forth on a regular basis you will not have issues.
Regular, for me, means about every 10-12 hours the type of programming is switched up, with the majority being 16:9 material.
Watch a game in HD once a week, and a couple of HD TV shows. Then watch movies as you please and some 4:3 programming (which you will hate to see before you know it).
I had a POS Sampo for 4 years which got minor image retention, but never burned-in at all. Despite playing video games on it, the TV just kept going without issue.
My Pioneer (6070) has exhibited ZERO image retention, and the Kuros are better.