The selling date of the Dell Venue Pro smartphone has been announced as being December 9. This is earlier than the previously thought December 14, when it was supposed to cost $150, but has been dropped down to $100.

That’s for the 8GB version, while the 16GB model will cost $150, with both versions attached to a contract from T-Mobile.

Without the plan, the Venue Pro jumps up to $450, which is also $50 less than initially expected. It’s the only WP7 phone with a vertical slider, so therein might lie the secret to its future sales, as well as the 4.1 inch AMOLED screen, a five megapixel camera, Wi-Fi and Bluetooth 2.1.