Laravel is the most mature, well-supported PHP framework I've ever seen. We just started using it as a replacement for CodeIgniter and I have one project in the field already and 2-3 more projects slated to be built on it already.

In our shop, we have critical needs to be able to support web applications for the long haul. Once I gave Laravel an in-depth look, we didn't hesitate to adopt Laravel for the long haul.

I would recommend trying to find a local meetup or just browse all of the commits on Github to see how active this community is.

I feel that Laravel is very active, and Taylor just announced that he will be dedicating every other week of his work schedule fully towards Laravel's development. Laravel is also built on top of Symfony from SensioLabs, and I know that Symfony has long term support for three years for bugs and four years for security. Taylor has also provided back fixes for security issues in the past.

I am lucky enough to use Laravel to maintain an application that was started over a year ago, and I've never had to worry about finding support while maintaining or furthering its development.

You can always reach out in IRC to get some more insight as well.

Laravel development is active NOW, but no one knows if it's like that in a year or so. Your question is really hard to answer, I guess it's like taking some risk or not.

If you are betting for a large application, You should have invest time in taking a look at codebase. As far as code of Laravel, It seems pretty straight to use it without any worry. In future, if taylor decides to stop development, there will be other groups/peers would love to take on from there. Alternatively, we can also develop our own version. ;)