I noticed that you have some questions regarding the usage of a Slingbox with the SlingPlayer for Android. Let me help you!
1. I have a legacy Slingbox (which works great, thank you). Will it work with my new Samsung Note?
The SlingPlayer for Android requires a Slingbox PRO, SOLO and PRO-HD.
2. The description of the HD Pro seems to imply that with that you can watch on smartphones. Does that mean that I don't need to buy the 29.99 app?
If you want to use the SlingPlayer for Android, you will need to purchase the application from the Android Market.
3. If I need to purchase new unit, can I have two units connected to the same TiVo?
This will depend on your TiVo. If it has available outputs for both Slingboxes, you can connect both devices to it.
The following link will give you more details about the SlingPlayer for Android: