Anyone else noticing this? I've had 7 for 2 weeks now (4s) and no matter how frequently I use an app it seems to reload when I switch back to it... Skype signs back in, safari page reloads, etc.
That behavior is governed by the developer of that app not iOS. Some apps can maintain a freeze state, others have to reload.
Also remember that the apps presented to you in the task switcher are either:
1. Frozen: not running but have held on to memory to load faster
2. Running in background: Only a few apps do this right now like Music, Pandora, Spotify and system apps such as Mail, Messages, Phone (althought you can close them they relaunch automatically).
3. Opened recently: these are just shortcuts to apps you had open at some point.
If you restart your phone you will notice a majority of the list remains. They are just historical.