This new version of PlugSuit includes the following:

Improved behavior with 64-bit applications on Intel-based Macs. Note that PlugSuit is not compatible with these apps; however, previous versions of PlugSuit tried to modify them anyway (failing silently). To prevent potential problems, this version avoids modifying these applications.
The version of SIMBL-style extenders (such as Afloat) is now shown in the preference pane. (It is only shown if it's not "1.0" or "1.0.0".)
This version introduces experimental support for extenders that load in Carbon applications. Currently no extenders from ∞labs take advantage of this support. (Extender authors: to load in a Carbon application, set the PlSSupportsCarbon key to YES in your extender's Info.plist file.)

This update is recommended to all users of PlugSuit.