My old Samsung plasma died after about 10 years of use. I've seen TVs last a lot longer, and whatever is going on with my Samsung, I'm pretty sure is power related. In fact, I've seen a number of TVs in the last year (client's of mine) die due to power supply issues... or so it seems. The issue doesn't appear to be with the panels, or the backlights, but with the power supply and shoddy components used.
It is unfortunate that things like this happen. Even moreso when you get a proper higher-end display where the components should be built to at least a slightly better specification.
I would call it a day and upgrade. But, it's not an easy choice to make.