This marks both a beginning and an ending of an era for WebOS which was purchased from Palm a year and a half ago as part of their acquisition. HP has since not been able to bring any innovative WebOS products to the market with attempts of the HP Pre 3 and the HP TouchPad only receiving lukewarm reception.
The fire sales of the HP TouchPad was probably the only thing which sparked life back into the platform, and with the transition to open source, all the TouchPad owners will hopefully have applications to use given that the platform gets a strong community behind it now that it is open sourced. This of course wont happen overnight and will take at least a couple of years to take shape.
By offering WebOS as an open source platform it will be interesting to see of device manufacturers show it the same interest shown to Android from Google. We know that WebOS is probably one of the better operating systems out there. While HP has assured they will continue supporting the development of the platform it will be interesting to see how a hardware company like HP will deal with this.
source - HP