The main focus of jQuery Mobile is NOT to be a competitor to native apps written in Objective C or even Sencha Touch. We aim to build touch-friendly UIs based on HTML5 for web apps and websites that are easy to build and work across a huge variety of platforms.
Sure, you can wrap a JQM site into an app with something like PhoneGap but I agree that a native app will always be more "native" and perfomant.
People never compare web apps built with jQuery UI to native applications created for desktop platforms, so it's a bit puzzling when we see developers try make comparisons between apps built with jQuery Mobile and Objective C. They are completely different tools, each with pros and cons.
The emphasis of the project is on embracing the web for mobile and I think that is the best way to judge the success of this framework.
We're actually using hardware-accelerated CSS-based transitions based on jqtouch. The difference is that jqtouch doesn't scroll you back to the position you were on if you navigate back - you always scroll back to the top, then transition so if you're on a long page, click a link, then go back you lose you place. We think that remembering you position is a very important usability feature that's expected on the web so this is included in jQuery Mobile. Unfortunately, it introduces a blink or jump which makes things feel much less smooth.
Page transitions, especially on iOS are an incredibly important issues for the team and we're actively working on improving this. In fact, we have 3-4 different branches exploring various approaches:
https://github.com/jquery/jquery-mobile/issues#issue/455
We weren't able to find a solution in time for a3, but this will continue to improve.
What specifically is slow -- touch events, scrolling, transitions, etc? We're working on bug improvements on all of these items so things will get faster, lighter and more responsive as we go. Oh, and work on more platforms (Nokia, Blackberry 5, Windows Phone 7). Feel free to log issues on the Git tracker.
Yep, we're very active on our @jquerymobile twitter account since the team gained access to it a week ago. We'll be posting code updates and soliciting feedback so follow us. Sorry for the lack of communication over the past few weeks, we've been heads down getting a3 out.
We're working on debugging WP7 now and will be pushing an update soon to make things work much better. We use media query support to decide who should be enhanced and WP7 doesn't support these so we need to add some code to let them in. We just got our first device last week but things are already looking good.
We're looking into every possible idea we can to shave file size and images down for mobile. Look for very aggressive use of CSS3 that falls back gracefully. We're hoping to eliminate all images (!) or radically reduce their use compared to current ThemeRoller. Using SVG is an option on the table for some elements but I think we'll end up using a TR style tool for this to generate static CSS for performance and compatibility.
It's definitely a goal to support fixed toolbars but we're still looking at how to achieve this cross platform in a lightweight way because these can be pretty heavy. We may end up offering a lightweight version that fades/glides in on scroll like the GMail floaty and hooks to support any scrolling fakery script you choose. Looking for input and ideas since were still at the R&D stage!
Sure, you can wrap a JQM site into an app with something like PhoneGap but I agree that a native app will always be more "native" and perfomant.
People never compare web apps built with jQuery UI to native applications created for desktop platforms, so it's a bit puzzling when we see developers try make comparisons between apps built with jQuery Mobile and Objective C. They are completely different tools, each with pros and cons.
The emphasis of the project is on embracing the web for mobile and I think that is the best way to judge the success of this framework.