Foundation http://foundation.zurb.com/ could be an alternative and it’s already responsive, however it looks like Bootstrap is going to be a “de facto” standard, so I would use Bootstrap 2 as it could/should be stable by the time that Yii 2 will be stable.
I will say I would like to see jQuery taken out of the core in a certain respect. The reason for this is that jQuery release schedule is alot more frequent that Yii’s and waiting for a new release of Yii doesn’t always work out (for widgets). Moving it to maybe the package manager but keeping the core integration would be a simple solution.
A proper solution would to move the whole thing into a adapter type interface still within the package manager so people can pick and choose what they want to use. This would give access for people to switch other libraries easier and extensions that use existing libraries could integrate better. I’m a jQuery junkie though so can’t see why anyone would want to use another library!
Well, how many people use the default Yii layout anyway? I use it only for a backend part and I don’t really care how does it look. Bootstrap looks nicely, but I’m pretty satisifed with the current appearance. Of course, Yii 2.0 should bring a new “style”, but one can always adjust the default look or use own design. Yii is a framework, not a CMS
i agree, but since you can transform it in a cms or whatever in five minutes, it is nice to have a good style setup to work with. as you say you can keep Yii style for some modules, like backends and some forms maybe.
foundation does have navigation menus with flyouts, tables with alternate coloured rows, form styles etc. Also (and I know this is a matter of taste) it just looks better and feels nicer to use than bootstrap.