This is not an 'at the moment' situation. This is an intentional security feature of the OS. You will likely never be able to store/read anything other than media files on an SD card with WP8.
how does that help security really?? if you have the document on the phone on the internal memory like you can now, what difference does it make if the document is on the same device but stored on the SD card instead?? if the phone gets stolen and you don't bother with pin numbers and sim locks it makes no difference.
i'm no great music expert, but i was listening to some of my MP3's over bluetooth using a sonyericsson HBH-DS970 and the sounded ok, i'm not sure what the people not happy are going on about??
a real gripe i have, as i use MS Excel for a some large files ( 23 columns x 3000+ rows ) is the autofilter function when searching by cell content. you can apply multiple filters, but unlike the desktop which only shows options in the next column that apply to the entries left after the first filter has been applied, the version in 365 on the phone shoes every option for every column regardless of what rows the previous filter (s) on previous column (s) have filtered out!! not very good at all.