It's still very early days, but Symfony 2 now has it's own site with some introductory material included. You can get the code and read about the framework - although there's no side-by-side comparison with symfony 1.4.
Now that versions 1.0, 1.1 and 1.2 are all officially dead (and 1.3 being a transitional version from 1.2) it looks like 1.4 will be the last stepping stone before 2.0.
And what's so different about sf2? Well for starters it looks like every component of the symfony framework has been decoupled into what they are calling "bundles". Hmm, that sounds a bit like Zend doesn't it? Interestingly, the Zend framework is one of the core symfony 2 bundles! Whoop! I guess that means you could use the Zend MVC in place of the Symfony one, hypothetically…
Additionally, your app is a bundle, too - although I can't think of any real expedient here as I doubt your app will be of much use without the other bundles. Perhaps this allows you to easily unplug it from synfony 2 and move it somewhere else… in a parallel universe perhaps.
Ironically, the sf2 site also publishes some "hello world" benchmarks which, while impressive, are still subject to the criticisms thrown at earlier benchmark results where symfony did not do so well - hello world is not an application where a framework is useful etc. Anyway here are the stats:
For the "Hello World" application, the Symfony 2.0 is about:
* 20% faster than Solar 1.0.0beta3
* 60% faster than Lithium 0.6
* 75% faster than Yii 1.1.1
* 2 times faster than symfony 1.4.2
* 3.5 times faster than Zend 1.10
* 5.5 times faster than CakePHP 1.2.6
* 69 times faster than Flow3 1.0.0alpha7
Anyway, it doesn't look to me like symfony is getting easier, but it is definately getting better. I am particularly looking forward to the new debug toolbar:
