Has cable announced any dates they will be doing 4k?
I was asking myself the same question 2 months ago & I'm really glad I didn't go with the 4k. Converted a movie to 4k to see what the file size was. At 35 GB for 2 hours, cable & many other industries are too far behind. Let's call it 20GB for 2 hours since my converter is higher than most. Newest 3D DVR by Comcast holds 100 hours, it's going to be a minimum of 1.5 -2 years in my opinion looking at those aspects. To me it wasn't worth the extra price if I couldn't use cable on it soon.
The new Panasonic, Sony, etc have come a long way yet Samsung still offers the best 1080 LED for the price on the market. Also, regardless of brand the majority of prices you see on the net are of 2013 models I found out, so don't let the 'good deal' deceive you. The 2014 model is a must if you're spending that. My recommendation is the Samsung 8000 series or the 7000. Pay the extra 50-100 for the 3D, even if you don't use it the picture quality provided on standard is just better. Love the Samsung 7155 we got, excellent purchase