LLC for Real Estate
First of all, if you purchase an investment property in some state, you should create an LLC in that state to hold this property in. It is also a good practice to hold each property in its own LLC.
You could still register a WY LLC in order to use it as a holding company for all those future LLCs you would form as you purchase the properties. In fact, you could hold those newly purchased properties in your WY LLC until you register LLCs for each property and move the titles, however keep in mind that some states tax you each time the name on the title changes (its a good idea to consult an attorney in each of the states you plan to purchase your properties to make sure you don't get surprises).