We live in a market economy (moderated by Government) so, IMO, the proof of whether a HEV, PHEV or BEV depreciates rapidly is evidenced by the market,,, not speculation or dodgey reports from overseas or "I had a convesation at the traffic lights with a bloke?
Over the past 2 weeks I attended 4 auto auctions in Brisbane that offered some EVs (mostly Toyota Hybrids and a few PHEVs & BEVs) and the hammer prices were much higher than their equivalent ICEs with none passed-in.
Granted, most of these were Government & fleet ist owner vehicles but IMO a public auto auction is a much better guage of value/depreciation than "hearsay" .
Toyota leads the HEV market by a long shot but over the past 12 months the Chinese are gaining traction. I'm just waiting for a pseudo-Yank poster on this thread to post that we too should bung 100% import tariff on Chinese EV imports so that US, Japan, Korean and European Multinationals here wont have their hip pockets robbed (poor things...bugger!)