It is okay to use the Intel HD 3000 for AE, PR and PS, but you will have much faster workflow with a dedicated GPU. I have the 9400M and the 9600M GT in my 2009 MBP and when I work with AE and lots of layers, the 9600M GT provides faster results when rendering in the Composition window.
Are you deciding between a 13" and 15"/17" MBP? If so, do you have an external display, as the 1280 x 800 pixel on the 13" is really a low resolution for AE? The 1920 x 1200 pixel I have on my 17" MBP can be quite low too on some compositions in AE, therefore I would at least look into the HR option of the 15", if you don't have an external display.
Also know, that when using an external display with the HD 3000, you will not really get fast performances with AE with big compositions.
And this might help you for your next thread/post: