There is pretty much zero chance of HP becoming a leader in tablets or smartphones - even as an Android box shifter.
Samsung have the android market pretty much sewn up, and Apple are kings overall..even if they could oust Samsung in the android world (can't see that happening) they would need an unprecedented effort in order to jump past Apple. Android may be outselling Apple at the moment but that's the platform as a whole - not an individual supplier.
The best chance they had was with WebOS, which was a lovely OS with a great backend+UI..such a shame that it has effectively died