So far, we have only one reported problem, which is that the AudioUnit validation tool in Lion is objecting to the few Silent Way plug-ins classed as ‘AU Generators’, resulting in Logic objecting to loading them. The plug-ins themselves work fine - it’s just a detail of the validation process that is tripping things up, which is arguably a bug, and we’ve reported it to Apple as such.
So if you use Silent Way and Logic, there seems to be reason to hold off upgrading to Lion. If you use our other plug-ins, or other DAWs, there are no known problems as of now.
The one slight oddity is when clicking on text boxes in order to type values into the GUIs. Normally this requires a single click to activate the text field (at which point it goes green) - when running under the 32 bit bridge, it requires a double click. Other than that, everything works normally.
If you experience any oddness when using the 32 bit bridge, let us know.