On the radios that have built in APRS (VX-8D is only one example) where the APRS frequency is set into VFO B wouldn't it be useful if the APRS packet could be optioned to report the frequency and RSL in dBm of the last contact on VFO A?
This would be a way of automatically sending signal reports via ARPS. The data could be mined out of the APRS data repositories and since you would have a geographic point with a signal value and frequency assigned to it you could create coverage maps in real time. While the frequency might be of limited use on simplex communications it would be valuable while monitoring a repeater output frequency.
I think that other than for EMCOMM, APRS is a technology looking for an application in everyday ham life.
This would require some firmware work on the part of the Yaesu's, Kenwood's and ICOM's of the world but would provide some immediate benefit of APRS. Of course the operator could select this option off or on and still retain the normal messaging functionality of these APRS capable radios.
As an aftermarket kit it should not be too painful for someone to make a small add-on kit that contains an A/D converter that could tie into a TNC on one end and to the AGC circuit of a receiver to even provide some level of functionality for RSL dBm via APRS. If there was a universal CAT interface to the TNC you could also pull in the frequency as well.