Just a few suggestions i have:
-Referee mode.
-Video Ref for those uncertain tries.
-More offload options - for example when player gets half tackled, there should be 2 - 3 players running off him, with you deciding who to offload to. (For example on PS3, press square, triangle and cross for the offload to different runners).
-Superstar mode - Create a player, choose your position/s, do tests, play trials with other rookies and get signed with a team and build your career form there.
-Coach mode - be the coach with your own set-plays, defensive structures etc.
-Referee shown on the field, and also licensed referees with own characteristics. Example if Steve Welsh is your ref, he would let advantage play longer and allow a more open game, but if Jonathan Kaplan is your ref you have more strict rules.
-Chip Kicks which may bounce in your or opponent's favor.
-Grubbers that work - not get tackled halfway through and knock the ball on.
-Easier to take interceptions - but only with key players that are known for interceptions like Jean de Villiers or Bryan Habana etc.
-If your get close to try line, have the option to stretch for the line - but running the risk to knock the ball.
-More try scoring moves.
-More line-out options - maybe 5 or 3 man line-outs with the looseforwards running off the flyhalf.
-Different defensive options (Rush, Straight Line etc.).
-Maybe a mini-game which include Sevens ??
That is all from my side - I'm not gonna mention to update statistics, better graphics or updated rosters - this is obviously something that comes with a new game.
Thank you for reading this and I am looking forward to an epic rugby game !!