Remember a post from someone deep in the bowels of BOM a while back. Lots of expense on AWOS installations. BaroVNAV was to be Australia's answer for our commitment to ICAO re-availability of GNSS based approaches.

Dick, could it be the Garmin gear has the capability although I fear you need a FMS to drive the approach and only those approaches depicted with a TWR or AWOS for a current BARO setting?

As already pointed out, Australian approach charts have distance/altitude scales, obviating the need for working out your own (unlike various other countries. Australia doing something better ? Whatever next). So no, I don't imagine going backwards...

As for us getting WAAS just so Dick can fly his Mustang coupled to the VNAV, #$%^&*( off. There are plenty of other options, as pointed out. Since when has augmentation been necessary for coupling down to the minima anyway? Other "software" does it nicely (in the boonies with no augmentation in sight), so get Garmin to change it's mind or change jets.

Barovnav is nothing special. It merely lets you down to a slightly lower altitude using a "Decision Altitude" technique, nothing more. And all you need is a chart with the LNAV/VNAV mimima for it and an accurate QNH from an approved source (as you do anyway for the 100ft MDA relief). Nothing new or expensive there. You've obviously got to have an approval for the gear...