Even if you could, you don't want to ... at least not yet. Its estimations on available memory are WAY off.
Yes, the "available memory" info that it gives is greatly inaccurate. But that's not what i use the app for (that's what Settings>Apps>Running is for).
I only use the task manager to "kill" or "close" the front-running apps that are running. For that use alone it's an app that would be great on my wife's 4G...IF there's a way to get it there, but it doesn't seem like there is.