I think you need to hold on to Walker, unless you get a guy in return, who will be a legit 6th man or better. He is by no means untouchable, but he also likely has much more value to the C's than he does in trades anyways.
As for his play....well, there was one thing I really took from last night. He took advantage of his opportunity. I know that doesn't sound like much, but after watching so many young guys over the years (including Giddens and POB) who have glided through their garbagetime minutes, playing very uneven, looking unmotivated to do much else than make a highlight film, it was just a pleasure to watch a young player clearly take that opportunity as a showcase.
Not only did he have a couple highlight plays on offense, but he played completely within himself in the offense. He moved the ball when he was supposed to, and asserted himself when he was supposed to. But more importantly, he played defense the entire 4th quarter, like it was game 7 of the finals. He was completely focussed, he kept his man in front of him, while still putting pressure on him, and he made plays.
Now don't get me wrong, I am not saying Walker should all of a sudden getting 20 minutes a game. I am just saying he was given a chance to showcase himself to his coaches, and he fully took advantage of it. That may not pay off right away, but it will pay off eventually...and I think it also tells us a lot about his character. That is the type of performance you expect to see out of a player who has the drive to be special.