If he stayed with Aberdeen for a few more seasons, he could prove to be a vital asset in bringing us up to the top 6, maybe even 3rd or 4th. He's obviously a very talented player, and he's at a club that has nowhere to go but up, which he could play a great part in. How could probably get a much better deal after a few seasons of doing good work with us then leaving now after just the one season. He's also probably going to win the AFC player of the year and goal of the year awards.
Sorry, but in my opinion both Considine and Vernon are more deserving of winning the player of the year award.
It would of course be great if we could keep Arnason but we have a good few central midfielders tied down for next season, including Rae, Milsom, Osbourne, Jack, and Hughes, so his high wage demands could be better spent elsewhere, such as signing a good strike partner for Vernon or getting Mark Reynolds in on a permanent deal.