I'm not following iPhone / appmarket news, but last I heard people had problems with (for example) camera apps rejected because they duplicate existing functionality. If it's not the case anymore, I stand corrected.
About .doc files though - I can also open them in OpenOffice on my box. But many lecturers sent me documents which were displayed completely incorrectly and contain auto-shape created graphs. Most students don't care either. That means I have to find MS Word to read them anyways. I don't expect this to be any better on iPhone/iPad, unless you can run OO or MS software on them.
Pages.app (for Mac, at least) can usually display most .doc(x) files properly. The only issue that I've run into is when a professor uses a font that doesn't come with a Mac. And, in that case, Pages defaults to Lucida Grande, rather then Calibri or whichever other font was used.
About .doc files though - I can also open them in OpenOffice on my box. But many lecturers sent me documents which were displayed completely incorrectly and contain auto-shape created graphs. Most students don't care either. That means I have to find MS Word to read them anyways. I don't expect this to be any better on iPhone/iPad, unless you can run OO or MS software on them.