I don't think they will make an "upgraded" version of DOA5. I have and played the alpha demo and from all the footage I have seen from E3, the game looks to be pretty solid. It seems as if they are going the safe route and basically building off of DOA4 and not doing anything too drastic. Move sets are similar, characters have the same feel, and I bet stages are structured similar to previous DOA games. The one thing I hope they improve on is the story mode (you could always improve in this area for fighting games).
Besides, Team Ninja already said no DLC characters and I don't think they would profit much by releasing an "ultimate" edition later on with only more costumes. DLC costumes offered on XBL or PSN seems more profitable than repackaging the same game with a code inside. Also I think the following for DOA is much smaller than when compared to NG. It's obvious that Team Ninja messed up on Ninja Gaiden 3. I am sure they learned from their mistakes and aren't doing the same with DOA5. Who knows, maybe the development time was much longer for DOA5 than compared to NG3.