I have just upgrade gnome-shell 3.0 to 3.3.9 and I was surprised. Almost no gnome-shell extension are not supporting. I find few in the internet which support new gnome-shell.
What do can I do to make my 3.2 extensions work in 3.4 gnome-shell?
I think that this is an issue with the metadata.json files, which stores the extension compatibility.
As 3.3 version of Gnome is actually an unstable version, I think that the extensions will be update to support it after the extension mantainers will test them.
That will happen probably after it will be officially released as a stable version and included in distro's repos (Ubuntu, Fedora, Debian, ecc) with number 3.4.
Until then, only the extension maintainers which are active developer of Gnome can test and update them.
Actually, if you are testing Gnome 3.3, the best thing you can do is to send a message to the developer of the extensions you are interested in and says them that their extension does or does not work.
You can download the extension as zip file and edit metadata.json with a text editor.
gnome-shell --version to this file and copy the extension to
/home/username/.local/share/gnome-shell/extensions/. Then ALT+F2 and r (for restart gnomeshell).
Then it is very possible that it works (but it can also kill your desktop). For me it worked on some extensions which didn't work any more after I updated gnome-shell.