Looking at the proposed native crypto browser support (should arrive in the
next year)

http://www.w3.org/TR/WebCryptoAPI/#EcKeyGenParams-dictionary

We see:

enum NamedCurve {
  // NIST recommended curve P-256, also known as secp256r1.
  "P-256",
  // NIST recommended curve P-384, also known as secp384r1.
  "P-384",
  // NIST recommended curve P-521, also known as secp521r1.
  "P-521"
};

I wonder if we might be able to get bitcoin's curve in there

For more background on Koblitz curve used by bitcoin see:

https://bitcointalk.org/?topic=2699.0