They keep saying 4K is coming.
I'll tell you this, 4K TVs sure have gotten cheap. It looks like you can get a decent sized one under $1,000. It always reminds me of the first flat TV I saw. It was 37", standard definition, and $19,000. We've come a long way since then.
Before you choose a 4K TV, though, you need to know that the current generation DIRECTV DVRs are not set up to provide any 4K programming at all. There are a few titles available on demand, but you won't see them on the menu when you're searching from the DVR.
Unfortunately the only way to get 4K content from DIRECTV right now is to use a DIRECTV-ready TV. These are the TVs from LG, Samsung and Sony that have a DIRECTV client built in. The most recent list can be found here
, although it's usually out of date by about six months. If you're buying a TV today, the best thing to do is ask the manufacturer. Using that built-in DIRECTV client will let you watch on-demand 4K content, although you'll have to pay for it since the only things on there are DIRECTV Cinema movies.
If you don't have a DIRECTV-ready 4K TV, unfortunately you're out in the cold for now. At some point DIRECTV will have some sort of box to control all 4K TVs but there's no clear date set for when that will be. Until then, you'll just have to be content waiting for the real live 4K content to show up, just like the rest of us.