This is a tough one that would need some thought.
On the one hand I agree that it wouldn't be nice for those users with non-Arm devices to not have any further development. However, having said that, these sorts of arguments have impeded progress in software in the past.
If you look at it with brutal honesty, moving to NaPP is the way to go for the future of iziBasic. It will take months (maybe even a year or more?) to redevelop iziBasic with NaPP, and you have to consider what the market will be like at that time. There will probably be less non-Arm devices around than there are now. Also, prices keep on dropping and by that time I would have thought there would be no excuse to not have an Arm device!
Also, if you talk about the future of iziBasic, then which is easier to develop further - non-Arm version with Arm applets or full Arm version?
It's not as if the non-Arm users will be left without iziBasic. The current version is very stable and works fine. However, as with computers and software in general, if you want more you will have to keep up with the times.
Even Microsoft is realising this and has stopped supporting Windows98 & ME. Also, if you want to upgrade from Windows98 to WindowsXP (or Vista now) you need a more powerful computer. This is the same with other packages that require more and more power. These things have to happen at some point if progress is to be made. It would be nice to be able to write rather faster games with iziBasic which can't be done now.
iziBasic is now a mature product in its current form. If Aldweb is now willing to put in the time to redevelop it, then I believe he should go the whole way, otherwise he will find himself in this situation again much sooner.
One could also consider what Palmsource (now Access) are doing. If the Palm operating system becomes Linux based, will NaPP be ported to allow iziBasic to simply be recompiled? If this is so, then iziBasic has to become completely Arm based to survive the change.
Hope this has provided some food for thought.
Thanks.