Yea ever since blackberry provided wireless sync this as been a problem. Everyone wanted the benefit of wirelessly syncing their personal contacts but then lost syncing from our corp contact list which is in public folders. I have to teach everyone how to copy from public folders up to a subfolder of their personal in order to maintain a sync'd corp list.
anyway, yes exch 07 did try to do away with public folders but after the outcry SP1 for exch07 brought them back. I'd imagine maybe the next version of exchange they will try to get rid of them again.
Regardless, RIM needs a way of providing corporations with wirelessly public contact sync for business addresses whether that is through public contacts or some other global list. No one in my company considers doing a GAL lookup every time a viable solution as it can double the time it takes to type a quick mesg to someone. Gal lookups are prob the only solution for companies with thousands of employees but if you are in the 10-500 range (and there are many there) you can easily sync it all to your BB.