I think that the industry is heading in several directions here in the US.

Firstly the switch to 'AC' lifts, with the solid state electronics associated with them.

Secondly, the trend seems to be in warehousing (as well as OSHA driven) away from propane and towards electric vehicles.

Thirdly with advances in fuel cells and the cost of electricity, (Wal-Mart is using them now) it seems apparent that the motive power source for electric vehicles will become fuel cells, not overnight, but I'd predict in the next 10 years.