I cam across this really useful tip over at A New Mac Tip Every Day. He describes how to use the System Profiler to check your applications to check the binary type. Remember if you are on any of the new Intel Macs you want everything to run in Universal or Intel.
Click the Apple logo on the top right in the menu bar.
Open “About this Mac” .
You will need to select the More Info… button, this will open System Profiler.
Move down to the Software section and make sure that the area is expanded.
Select Applications – this will show you all the applications on your machine
To see which binary they are sort by the kind column and there you go you can see if anything needs to be updated.