Wondercon ran from March 24-26 at the Anaheim Convention Centre, and yes, there was some very good cosplay on display.
Photographer Jason Laboy was there taking some shots which he’s been kind enough to share with Kotaku; you can see a lot more at his website.
Note: this being a con it was tough getting credit information for many of the cosplayers. If you recognise/are any of the cosplayers below, let me know and I can add a credit!