I've mainly seen this problem with doors and wall textures not loading their high-res versions, but I've experienced sporadic texture problems with whole areas. In my experience, the issue inconsistently comes and goes, which is how I know that it is a technical issue rather than a problem with the actual textures as designed. The effort put into textures here is obvious, which why this particular issue is so galling.
I have uninstalled and reinstalled the game to the 360 and this is still occurring. In case this is an optimisation issue with the console model, the Xbox 360 I use is a 60Gb Elite (approx. 2009).
It does not damage the great gameplay in any way, but does ruin the immersion while playing. If the problem is not widespread, it may not be a priority for the first patch, but I'm sure those people who have experienced this issue would prefer to see the game as the developers intended.
It'd be great to know if this is a known problem and if anyone else has had this issue, please contribute.