Thank you Manecca, Ben and PTravel, for your feedback.
A good thing about this forum is that it isn't segregated into 'point & shoot' & 'DSLR purist' sections , or canonTalk, NikonTalk etc, like other camera forums .

I think a DSLR is overkill in cost/weight terms for scenic holiday photos, IF I can get a decent prosumer/wannabe almost-DSLR, like an updated Canon S~ IS series (or Leica/Panasonic/Nikon/Olympus/Sony/Fuji/whatever) that does as well as a smaller unit can do, with a 10/12/15/18x zoom and as big a sensor as possible.

It seems Canon isn't releasing a S~ series yet and Olympus has scared a few people with its new 18x zoom model.
Maybe I should just look for a Canon S2/S3 on eBay - but if you can recommend something better, like the Pana/Leica or whatever, let me know - especially if it has a larger sensor, so that it improves on the performance of these mid-range P&S models.

Any other advice on photography in Hawaii is most appreciated.
As some say in Australia - TA!