Another developer has created a Quick Look plugin that accesses the contents of all types of archives:
From the site:
The currently supported archive formats are: ZIP, TAR, GZip, BZip2, ARJ, LZH, ISO, CHM, CAB, CPIO, RAR, 7-Zip, DEB, RPM, StuffIt's SIT, DiskDoubler, BinHex, and MacBinary.
The software costs $19.95 and comes with a one month free trial.