The arcade version is scheduled for release this month in Japan while the console versions (PSN/XBLA) will be released sometime next month. The game will feature full voice acting and will remain faithful to the arcade version.
Accent Core Plus R will basically have more balance in terms of gameplay as well as new character moves not existing on the Core Plus-only title.
Arc System Works is the same developer and publisher for 2D fighting game BlazBlue which had a Vita and 3DS versions as well.
For updates about the Guilty Gear XX Accent Core Plus R Vita version make sure to come back frequently at vita.game-rumble.com or you can sign-up to our mailing list and get up-to-date information about the game right to your inbox.