If you have been a long time BlackBerry user this information will likely come as no surprise. However, if you are new to the BlackBerry world this is something to pay close attention too. Currently there are no themes available for the BlackBerry Tour (for free or for sale). This is based on the fact that the tools needed just simply are not ready as of yet to create and design themes for your device.
The company (now owned by Research in Motion - so I guess there more like a division) that creates these tools is Plazmic and for the longest time now Plazmic has had a bad habit of not having in place the necessary updates to the Plazmic Content Developers Kit so theme makers can have it prior to / at the time of a new device launch. This often means it's usually 2-6 months before theme developers can get ther hands on software needed to make all those free and premium themes you see now for existing devices.
Why it takes so long and why Plazmic cannot have these tools ready for developers is really unknown to me, considering the same process is used to create the themes which come preloaded on your device. And in the case of the Tour, the screen resolution is the same as the Curve 8900 - there really isn't much "new" here. Developer tools and their readyness is something RIM truly needs to work on. Even if it is just themes, it's still a big aspect of the BlackBerry ecosystem that RIM is neglecting.