I like my NEX-5. I have been using it almost exclusively since I bought it in December of 2010. I probably shot over 10,000 frames since. But, the current NEX cameras need some serious feature upgrades.
First and foremost, please, please add a built-in view finder, in the same class of the Panasonic G or GH series, or better. I am in my 40s, and I can't see screen well at close range with out, er, bi-focals. I have ordered a pair of progressive lens, but still not done yet. So I don't know how well it will work out. Another benefits of a viewfinder is the accuracy of focusing. Shooting DC style, it's difficult to get critical focus, especially at close range or very thin depth of field, because a slight movement will shift the focus. Heck, I will even settle for an external EVF!
Second, I would like a few more physical buttons on the camera. As it is implemented currently, changing settings means going deep into the menus, and is a pain in the neck. Even just a mode dial will make things much better.
Third, fix the %T^@#$ tripod mount! I don't mind a slightly larger body, but make the tripod mount flush with the bottom of the camera. The NEX-5 has the most unstable camera support of any camera I know.
Fourth, more lenses! How about some nice, FAST autofocus prime lenses? All other EVIL makers have better lens than NEX, if you count only the native mounts.
I am sure there are a few things I would like to have, but the above is my main concerns.