Using a single form - multiple panels/user controls that become visible or moved into a view has been a valid techinique when creating mobile applications. And bringing the panels into a view would be much faster than navigating to a different form.
However this technique should be used approprietly and few important things should be taken into consideration. First of all, a multiple controls and all associated umnanaged recources (window handles, message pumps, graphic contexts etc...) would
be created. Eeach would take device's memory and processor cycles plus the data required to populate the contols. So you should always measure how your application would be affecting the performance of the device or how it would behave in a more memory constrained
Secondly, this techinque could affect the load time of your form when it's shown the first time. You may need to show a splash screen to a user to make him/her know that something is happening.
Thirdly, the maintainability of a single form - multiple panels application is somewhat worse than a multiple form one since a lot of your UI look depends on the positioning of the each of the panel and you will also have a lot of UI related code in
one class module.
But if your application consists of a few views and there's not a lot of data associated with it, you should be able to use this technique. The Mobile MVC should be able to support this. I'll try to come up with a sample soon.