There been a number of evidence pointing to a smaller Nokia N97 Mini that is rumored to be formally announced this September during the annual Nokia World 2009.
The Nokia N97 Mini will have a smaller 2.9″ screen at 640×360 pixels. See photo below for comparison {via}:
Storage will also be bumped down to options for 8GB and 16GB. And of course, they will also be cheaper. The Mini N97 looks legit since Nokia has been doing the same positioning with the E63 for the E71 and the 5530XM to the 5800XM.
This might indicate that the N97 was a success and Nokia just wants to offer the same to the low-budget market.
waiting for the release.