We saw a lot of discussions in the Forums and we had an internal discussion about this message:
One known large discussion thread:
And yes this is definitely a false alarm.
Credits goes to one of our Italian customers who asked for a hotfix and the official solution is as follows for SharePoint Foundation 2010 and the Search Server Express 2010:
See a message stating "Trial period for this product is about to expire" after running the health analyzer within Microsoft Search Server Express.
By default the health analyzer rule “Trial period for this product is about to expire.” is enabled. This looks for the licensing module which doesn’t exist in Microsoft Search Server Express as it’s a free product.
Go to Health Analyzer -> Review Rule Definitions and disable running the rule "Trial period for this product is about to expire".
Disable the CheckBox.