Question: When is an iPhone like a BlackBerry? Answer: NEVER. Sliding a physical keyboard out of your pocket and onto the iPhone to type won't cut it if you actually need real keys. Switch to Verizon and get the RIM phone already.
Regardless, you should run out and buy this product for $29.99 when it ships on November 19th. It's going to be a collector's item in the museum of "Can you believe someone actually thought this was a good enough idea to put into production?"