Hardware similarities... not sure. Perhaps only the color, and the bulky size. With the PS4 being slightly more powerful, it might be even slightly bigger. The latest PS4 video ends with a blue LED light, so I expect some blue LED on the black console, too. Should look stylish. Other than that, Sony doesn't have much (good) to copy from today's Xbox showing.
As for the online DRM stuff...
I predict PS4 will also require games to be installed, but instead of the 'be online and activate code' method of Xbox One, it will simply require the disc to play the installed game. If you borrow it, you can't play it anymore even if it is installed. That simple (just like X360 works right now with full game installs). So, no, I think Sony won't put the online checks in PS4 to keep looking if your installed code is valid.
IF companies like EA try to force Sony to do this DRM stuff, Sony will probably just stay neutral and say it's a developer decision so that the blame is the developers'.