I think I have some good news in regards to access point mode on the Overos.
I took the GPL’ed code from Marvell for the “Dreamplug”, fixed it up, and got it working with the micro access point (UAP) firmware for the SD8686 which can be found in the Palm Pre jar files– all of this on a 3.5.0 kernel, but I would expect it to be fine on newer kernels as well.
Without any trouble, I was able to achieve 10+ Mbps with WPA2 encryption enabled.
You can find everything here:
The README gives instructions for finding the firmware as well.