Thierry,

Gartner started saying in 2013 that 50% of apps will be hybrid by 2016- meaning using HTML for display as part of the app, which won't be in a browser. Then at the end of last year, Forrester agreed with you, saying that web on devices will take over from native the same way it did on Windows. ( https://www.forrester.com/Web+Hybrid+And+Native+Mobile+Apps+All+Have+Their+Place/fulltext/-/E-RES61154 ) But just a few months later, observers now say that the native vs HTML battle is irrelevant on devices because most business apps already are hybrid.

Have you checked out Lianja? GUI in HTML5/CSS, language-agnostic interpreter behind the scenes. Seems to me this model is the likely future: separate out the GUI and a cross-platform behind-the-scenes interpreter is easy enough. Look at the complaints about old cross-platform FP and it usually boiled down to GUI glitches.

Meanwhile Google is coming up with new tech like Soli and Jacquard that customers will expect to experience even if their browser is old. IMHO ports of Windows apps are a 2015 phenomenon as customers start to look for the clever features that made them choose their device...