Trying to Piece Together BB10

Yes I realize that I will have to wait til it is released to know how it will truly work but I am just looking for a few opinions on the upcoming OS.
As a video and a few pictures demonstrated, you swipe left into the screen using the right side bezel to view notifications...messages etc. But then how do you get to the next app? Like on the playbook, if you swipe left into the screen using the right bezel, then it will bring you into the app that is to the right if it. but with the video of BB10, it brings you into the messages app. How will this work?
Also, are widgets better than having apps "minimized" like you do you on a playbook? I see android phones will all their nice looking widgets for weather and stuff but do widgets slow down the phone more? I know they slow down computers, that's for sure.
With the 2x2 grid shape that bb10 will have for opened apps is pretty much just as convenient as having widgets on your home screen. Especially if you set your apps to "showcase", then the apps will be live just like widgets are.

BB10 does not have widgets, it is a glance view of each running app. Its like when you minimize a Playbook app, it is still live but it is smaller. They had to change the look of each minimized running app as it would have looked weird otherwise. As for switching apps I to am curious. I love bezel gestures, pure genius and extremely useful but, I am not aware of an active bezel being added to BB10 phones. Not that it won't be or will be, I just don't know.
In my opinion and experience widgets slow down everything. Newer Android phones may not have such a horrible problem with them but I know the ones from a year ago lagged. I also had a bad experience with widgets on Windows Vista in the side bar, I find they are not useful or very helpful. Of course that is just my opinion.