There are a lot of challenges to bringing Hero Lab to a smartphone, both in terms of "how do we fit everything on that small screen?" and more technical issues.
For example, my gut feeling is that the smartphone market will end up irrevocably split 3 ways. Apple, Google and Microsoft will each have ~30% of the market, and it's looking like it'll be almost impossible to develop software in a platform-neutral way.
That means if we did do a mobile solution for one of those platforms, it would be very hard to port it to the other platforms without completely rewriting it. Not only that, all 3 of the platforms above would require substantial rewrites of Hero Lab before it could run on them in the first place.
So unfortunately whatever we do for a smartphone app - if anything - we'll end up disappointing a lot of people.
That's not to say that it wouldn't be awesome to be able to create characters using your smartphone - we're definitely looking into the process, we just don't have anything to announce yet.