No DVDs are not a big problem, blu-ray has more space so it is more convenient, but that is pretty much it. No one had any problems with 4 CD games that were released on the PS. Developer can use multiple DVD and/or include codes to DL items.
Star Ocean was released at a later date on the PS, it was required for them to include additional content for it to be released on the PS3. Uncharted and MGS is possible on the 360, if the developers are willing to do it.
As for blu-ray being the future, that is questionable. More like it is the present, but the next format is already on the horizon and it will very likely be feasible before the next gen is released.