[T-Mobile Samsung Galaxy S II SGH-T989] Splaktar:
CWM 5.0.2.7 non-Touch recovery as recommended in the OP. I let the super wipe script do all of the wiping and don't wipe with CWM.

OK, I just hit this with a fresh v4 install. Absolutely no data has been restored to my device from backups. I did let Google restore apps and I went into a number of them to login/configure.

Here are the steps leading up to hitting it and (whether or not they have been involved in previous reproductions):

0) Connect to WiFi. WiFi-Calling enabled. (always)

1) Play some music via Google Music or some other streaming source. (always)

2) Stream the music over BT (most always)

3) Have the phone plugged into USB charging on a desktop w/ usb storage off (most always)

4) Browse around my home screens which contain about 13 widgets on 8 screens (always)

5) Add remove and re-add widgets to a screen (sometimes)

6) Launch a previously unopened app (since reboot) from a shortcut on one of the home screens or from the app drawer (always)

7) Re-use an app that has recently been opened (always)

It is not as if following these steps one by one will reproduce this within 5 minutes. But this clean install lasted me only 1 hour 5 minutes before this app launch hang occurred.

This last reproduction I had just restarted my Launcher (Go Launcher EX) and was in the middle of re-adding a widget, but when I clicked on the widgets icon to open the list, nothing happened. So I gave up on that and backed out.

Then I opened an app on one of my home screens and it highlighted, but did not launch or open. Then I went to try some other apps with the same result. I also tried some in the app drawer, same result.

So then I long pressed home and selected an already open app. It came up just fine. I was able to use the app and then finally go back Home without any issues.

I also got the task manager open. I'm at 667/769 MB RAM. System storage is at 0.93 GB / 1.97 GB. USB and SD card storage are not close to full either. There is only one active app (the one that I just had opened). I did 'Exit All' and then closed task manager and tried to open an app. Same hang.

Try to access settings via widgets, nothing. Try to do Menu->Settings, nothing.

Try to open another hanging app, highlights, then nothing. Wait 5 minutes or so and the app, sort of opens... I get the title bar at top and the rest of the app is all black. Wait 5 more minutes, nothing changes. Can't go back to get out of it. But home takes me back to the home screen.

Open Phone app, it opens, but the back button from the app lags and does nothing, then finally instead of taking me back home, it takes me the last hung app w/ just the title and black screen.

Home again takes me out and back to the home screen. Menu works, so I do Restart of the Launcher. This results in the wallpaper displaying but the launcher does not ever redraw the screens (hung). Only the notification bar works at this point.

I guess I'll try to grab a logcat now since it's basically completely hosed now... no luck with a logcat. Can't get the device to show up in adb. Maybe USB debugging is still off since this is a completely fresh install w/o any data restored.

Edit: Rebooted, USB Debugging was turned on, but I guess it just couldn't launch it when it was connected. Device shows up fine now in adb.