Sounds great. I wonder if any of this will make it upstream in time for 1.5.
It might - the proposed changes started review before the freeze for Go1.5, but the main change (the assembly implementation for elliptic curves) is currently in legal review. Depending on how long that takes and its outcome, it might make it.
For those interested in the status of these changes getting merged to mainline Go, here are the CLs for them:
https://go-review.googlesource.com/#/c/8968/ - assembly implementation of P256 for amd64
https://go-review.googlesource.com/#/c/9253/ - Simple Montgomery Multiplication to accelerate Mod-Exp