Just for interest's sake can anyone point to this 'promise' of a free upgrade to version 2? I bought TM1 and it played no part on my buying decision because I was not not aware of any such guarantee.
If this promise was made then IMHO his best option is to adopt the Firefox/Chrome numbering scheme: stabilise and release whatever he has now as TM2.
He should also change the licensing to free updates for 12 months from date of purchase and continue working on TM3.
See for example the "license policy" page [1], where it says, "We do hope to release a free 2.0 upgrade (which will require Leopard) but we provide no guarantees about this, we do not promise what features it may or may not include, we do not have any expected date of release etc."
If this promise was made then IMHO his best option is to adopt the Firefox/Chrome numbering scheme: stabilise and release whatever he has now as TM2.
He should also change the licensing to free updates for 12 months from date of purchase and continue working on TM3.