He's one of the more talented goalies in the league, but he hasn't showed it consistently this season. He's been up and down, mostly down. 12 wins in 38 appearances isn't what he or the Ducks were expecting. He's hovering around a .900 SV% which is surprising for the Swiss goalie who is usually around the .920 mark. There is no competition in goal in Anaheim so he will continue to get the bulk of the games, I think he will have a great second half.
After enjoying a nice run at the start of the month, his last couple starts haven't been very good at all. Now it looks like the Leafs will turn to James Reimer once again. I think once Reimer gets a couple starts in, that Gustavsson will return to the spot-starter we all thought he was going to be anyways. His numbers aren't even that good (.906 SV% & 2.92 GAA) so dropping him won't cause you to lose any sleep.
One of the most underrated talents in this league is Mark Streit. Many thought there was no way he could come close to duplicating his 62 point season he put up in 2007/08 with the Habs, but he's put up respectable 56 and 49 point seasons, he's on a similar pace this season. His minus 17 +/- rating isn't pretty and isn't Streit-like but he's an offensive force. The Islanders are full of quiet difference makers - Matt Moulson and P.A. Parenteau to name a couple.
He's on pace for over 30 points for the first time since 2005/06, so why consider selling him? Well you just answered the question. That 38 point season was over 5 seasons ago, and there's a reason why he hasn't gotten back to that number. He's just not that kind of player, he's a shutdown, 2nd pairing kind of guy. See if you can swap him for a defenceman that gets into the 30+ range more often.
One of the early surprises of the year has kept up the pace, I've slotted him in for around a 60 point season. Not bad for a player that started the season on most leagues waiver wires. However there are going to be GM's out there that think that his run is slowing down and running out of steam. I don't think that's the case at all. He's playing a lot of minutes with Jamie Benn which only means more points for Ryder.