It depends on exactly how much you end up having to optimize for each platform, and how much reuse you get between platforms.
If your app is a simple broacherware+notifications app, then HTML5 is probably the way to go.
If you can afford expert developers for every platform and mobile is critical to your success then 100% native makes sense.
There just isn't a simple answer here. To quote nostrademons:
I'm still not sure which technology is, on the whole, better for mobile apps. But one of the signs that you actually understand a problem domain is that you can give advice more specific than just "Competing technology X is better than competing technology Y"
If your app is a simple broacherware+notifications app, then HTML5 is probably the way to go.
If you can afford expert developers for every platform and mobile is critical to your success then 100% native makes sense.
There just isn't a simple answer here. To quote nostrademons:
I'm still not sure which technology is, on the whole, better for mobile apps. But one of the signs that you actually understand a problem domain is that you can give advice more specific than just "Competing technology X is better than competing technology Y"