In my experience users tend to bookmark, email, share or “copy-and-store” links to interesting (web) content. And this is good. User help spreading your content. This is however not possible in an native app – there just isn’t any address to copy/link to – and therefore, in my opinion, you should avoid native apps in any case where you have any form of public content. Games and other applications may still benefit from native solutions.
This becomes even more relevant when we are talking about tablets. And as performance gets better in these devices along side with web techniques getting more advanced and capable this becomes further more important.