My original proposal was to configure javaws w/o path, so that the default javaws in the system path would always be picked up.
This works fine if both 32 and 64 bit versions are installed, however, if just one is installed, it leaves a dead link for the other browser.
I think now, we should first do exactly what we do now, then if and only if both 32 and 64 bit versions of java are installed, register the mime type w/o the full path, so 32 bit browser will get 32 bit javaws, and 64 bit browser will get 64 bit javaws. and if say only 32 bit java is installed, both 32 bit browser and 64 bit browser will invoke 32 bit javaws as now.
Longer term we should make javaws capable of launching 32 or 64 bit jres, using one launcher and respecting the -d32 or -d64 vm args as is currently done in the java launcher on Solaris.