Regardless of framerate, I think this game will be really fun just to mess around in. Its not a competitive multiplayer game, so some drops below 30 fps don't bother me as long as they are during scenes of heavy chaos, where I wouldn't really be able to react anyways. It may result in a few unwanted/ unneeded deaths, but I think how silly and fun it looks will out weigh many of the framerate issues. I have seen a great deal of footage, which includes those issues of pop in textures. Among the chaos, they didn't seem as noticeable, but I bet some people would really take issue (the reviewers especially) with the pop in. As is usually the case though, visuals have less of an impact on score than how story, gameplay, and mechanics all fit together. It never seemed to me in the gameplay videos that the frame rate drops were devastating, and the impression I got from the journalists in the gameplay videos is it seems as though the framerate issues were almost entirely fixed. would never say that Microsoft shouldn't have focused more on the hardware, and no one is saying that they wouldn't have loved for this to be locked in at 30fps, but I bet a good deal of people can tolerate sub 30 fps.
It will be interesting to see what will happen as the development tools for the Xbox One mature and possibly the locked 10% of the GPU becomes accessible (to me 10% seems like a large amount to lock away). It'll also be interesting to see what the programmers will end up doing to try to work around the issues of the Xbox One, and see what percentage of the market share it will hold. It is worrying to me (a day one buyer) to see this development struggle with the system, and a lingering question remains on whether or not the ports of 3rd party games will start to become sub par compared to the PS4 version (something outside of the resolution difference).