You can see the changes from the log since 1.5, but having the same functionality available from the timeline would be useful as well. Select a revision in the timeline, select the file in the "Files changed" list of the Changes tab of the Inspector, and see the changes of the file in the main view.

Will this be just the library built in, or will this update include the new sparse directory exclusion as well? As far as I can see, this seems to be the only client-side UI enhancement coming with 1.6.

A good starting point for merge implementation would be to allow undoing commits. I tried several ways here, including the Working Copy>Revert... menu command. Nothing seems to be working. I had to do it using the command line. This could actually look like Update... or Revert... but execute a "svn merge -c -<rev>" instead.

I would give 10 votes here, if I only could.

This feature is actually easy to implement (just a single edit field for a start) and it would be another situation where the CLI could be avoided.