I have seen this come up a few times so I wanted to try to clarify it here, the Mistral EVM actually has OMAP3530 silicon on it. Unfortunately given the orderable part number of the EVM it gives the impression that the board comes with an OMAP3503, this is not the case, the Mistral EVM is capible of using the SGX (3d graphics accelerator) and the DSP (C64x+) capabilities of the OMAP3 platform.
The reasoning that the EVM was originally labeled with 3503 is because at the time of release, the software package only supported the 3503 featureset, essentially just the ARM without the SGX or DSP, now that the DVSDK is available from www.ti.com/omapregistration in beta the DSP is usable, and soon there will be a software package to make the SGX usable with an OpenGLES driver.