Having Ambient under the GPL is good. The linking will be no problem for most cases.
If your program does not make use of any Ambient functions which came with the GPL release, then you can link it with the pre GPL includes and you are safe.
So all current software which is unaware of any possibily new functions can use the old includes and is save. Whether the user actually uses the new or old library does not matter.
Exampe: Last year MySQL changed its license from LGPL to GPL. So linking against the new MySQL binaries will require that your app becomes GPL too. But as the new MySQL version are backwards compatible you can just link your apps against the old LGPL version and your programm does not need to become GPL. Only apps which make use of the new function need to be linked against the new library. For the record: MySQL is offered under multible licences, so commercial apps can use a commercial license and be save, GPL apps can always use the GPL licensed version of course, and for all noncommercial users there is another non GPL license - so PHP and BSD apps are free to use MySQL as well.
So for all our MorphOS apps its safe to use the AMbient libs as long as you only use the functions which were available before the GPL release. As soon as David offers the libs under LGPL you can use all new functions too.
