No. You can restrict the input (if the user click on a char it won't work) by using the textField.restrict propertie, but you cannot trigger the numeric keyboard in the actual version of AIR.
In my case, I implemented my own numeric keyboard since it was a huge issue for my project.
It looks like this is implemented in Flashbuilder 4.6 through the softKeyboardType command:
<s:TextInput softKeyboardType="number" />
Here's a link to good article on it:http://devgirl.org/2011/11/29/flex-mobile-development-flex-4-6-cool-new-soft-keyboard-feat ures-sample-w-source/