I'm going through and documenting some of my responses to the above comments about CakePHP and some of it's (in some cases rightly) perceived faults.
Big websites are run using CakePHP, some being Mozilla Addons, Scratch by MIT, and Hot Scripts. There is a bigger list right at the bottom of the CakePHP website (http://cakephp.org). Regardless, any good developer should be able to build a scalable website using a framework as long as the framework isn't completely silly (CakePHP isn't too silly :D ).
It is true that there isn't one very good (free) CakePHP tutorial that goes through every feature of the framework, but the documentation is extremely well laid out and verbose. Anything that isn't clear can be cleared up through the Google Group and on IRC, and we welcome any and all changes/corrections to the documentation. Documentation is not just a core developer issue, as many things are application specific and people come up with interesting tips and tricks, and so thusly everyone is invited to contribute (Not just comment!). Of course it is all moderated, so most of the cruft/spam is not added.
The code is modular in that you can add in new code that supercedes core functionality. Much of the code is simply PHP classes. It is true that writing such functionality may be a burden, and I have not tried using alternate classes as fillins. Yes, it does not handle other ORMs, so you are stuck with the default, but this should be fixed in Cake3, which will be able to mix and match any other PHP classes at will (that includes Propel and Doctrine support).
The CLI is very good, and it is easy to extend for App-specific support. One example is that I recently developed a shell plugin that would automatically install any other CakePHP plugin that I have indexed from github. Took about 5 hours to build something extremely usable and flexible. I'm sure such functionality exists for Symfony, and it DOES exist for RoR :)
As for being Rails-like, it is and it isn't. Many things are similar, they are MVC frameworks after all, and CakePHP goes for the "Conventions vs Configuration" approach. PHP4 support mucks with a nicer syntax, which Symfony doubtless has because of PHP5-only support, but it is still extremely usable and intuitive. The framework does not provide EVERY feature of Rails out of the box as it isn't a straight clone. CakePHP is a framework, not a library (hi Zend), so it won't provide everything out of the box.
Generation of views is, I agree, a bit wonky in CakePHP. It is being greatly enhanced in CakePHP 1.3 and 2.0. It will support custom templates for each and every Model, View and Controller (as opposed to just a type of view as it does now). Also, there exists a set of shell tasks on github by a user going by neilcrookes that auto-bakes only certain types of views (including only admin views) which can be used in combination with custom templates to produce exactly what you want. CSS styling also helps :) but this is definitely something that can be improved.
CakePHP takes many varied parameters in it's Model::find methods, although in certain cases it may be useful to use raw SQL queries. The Model::find() method is very flexible and has not failed me insofar as creating complex finds. I suppose that is related to being comfortable with the ORM, which inevitably always takes time.
Form validation should logically be in the model layer, as that is where any action related to the database is being performed. You can specify alternate validation in a specific view I believe, or swap validations (there is a behavior for this but it wouldn't be hard to do so without it).
Multidimensional arrays are a bit silly, but you'd still likely have multidimensional objects. PHP4 had a broken Object Model and so that is why CakePHP does not use objects. This is being corrected in a future version of CakePHP (as I pointed out above in a previous comment), but it is useful to have a framework that supports PHP4 in some cases. Again, YMMV and I agree that full PHP5 will be a great boon, both in speed of the application and of development.
Databases can be swapped out at will. CakePHP does not allow functionality that is inherent in only one type of DB (hence the dropped support of ENUMs that are only in MySQL), so that the ORM is always supported and can always build valid queries. You can have multiple databases in an application, one per each Model if you wanted, and can swap them at will or even not use a database at all for a specific model. So no, it is not tied to a specific database.
In the end, your choice is your own, and I wholeheartedly suggest looking into both and reading through the documentation, checking out the Groups, IRC channels, blogs and any forums for both and seeing which framework suits your development style the best. Reader beware, I'm a CakePHP developer so my post has some bias.