A few interesting questions came up during my presentation at Northeast PHP yesterday. People wanted to know whether jQuery Mobile could be mixed with MVC frameworks such as Backbone or with responsive frameworks such as Bootstrap.
You must also understand that jQuery Mobile is better suited for content sites rather than highly interactive applications. It is also meant for creating mobile-only sites, not for creating fluid and responsive layouts.
Also don’t use jQuery Mobile solely because you like its appearance. If you only care about the CSS classes and not about the progressive enhancement, then you should simply keep the CSS. Use whatever other framework you prefer and apply the styles that you like.