Set to new and change the target.

I can reproduce the bug.
The behaviour is very strange.
- Make sure that the layouts pane in the tasks bar is not selected
- Choose format layout
-> nothing happens
- select any other Tasks pane
-> the Layout pane appears.
Please have a look.

Accepted.

I raised the priority, as I don't see any way to change the slide layout.
(I have a customer presentation due today!  Yikes!  If you know of a workaround,
please let me know asap.  Thanks!)

What's the Layout Pane?  If I go to the menu View/... I see:
Task Pane
Slide Pane
Toolbars ->
Status Bar
Input Method Status
...

The Format->Slide Layout menu entry or the 'Slide Layout' tool bar button simply
expand (or should expand) the 'Layouts' panel in the task pane (the right pane
with title 'Tasks').

The 'Layouts' panel can easily be expanded manually by clicking on the 'Layouts'
entry in the task pane.

Because this simple workaround exists I change the priority back to P3.

Format->Slide doesn't do anything.
The "Slide Layout" on the Presentation toolbar doesn't do anything.
The Format menu doesn't include a Layouts pane(l).
This is still the case in OO 2.2.1 on Linux.

I can reproduce the bug, the you can't change to the layouts pane with the menus.
You can change to the layouts pane with the marker tab in the Tasks pane.
If there is no marker tab for layouts maybe it is deselected in the view drop
down menu of the Tasks bar. Please have also a look to the attached screenshot.

Created attachment 46673 [details]
screenshot of the layoutspane

Thanks for the screen shot!  It took me a few minutes of experimenting to get
the Task Pane to appear.  The Task Pane had already been enabled, but it had
been squished down to a very thin line.  (In my 3 years of using Open Office, I
had never disabled the Task Pane, nor had I ever seen it!  I use Open Office for
most of my work, so I use it daily.  I consider myself an advanced user.)

I found the Task Pane by toggling the visibility of the Task Pane on and off. 
After doing this about 10 times, I found a very thin line between the main pane
and the formatting pane on the right (whatever it's called). I then played
around with the vertically-oriented horizontal resizing bars, moving them left
and right.  Eventually I got lucky, the cursor happened to land on the bar for
resizing the Task Pane instead of the main pane or the format pane.

Now I have my work-around for the Layouts. The bug still exists for the Slide
Layout button on the task bar and the Format/Slide Layout menu.

I've attached screenshots with the Task Pane enabled, disabled, and expanded.

Created attachment 47156 [details]
My default layout with the Task Pane enabled, but barely visible

Created attachment 47157 [details]
A picture with the Task Pane disabled.

Created attachment 47158 [details]
A picture with the Task Pane visible.  (Finally!)

set target from 2.x to 3.x according to
http://wiki.services.openoffice.org/wiki/Target_3x

As this one is a regression I move the target back to 3.0. 

Fixed by using the FrameworkHelper::RequestTaskPanel() method to switch to the
layout menu (called in ViewShellBase::Implementation::ProcessTaskPaneSlot()).

Modified files:
/sd/source/ui/view/ViewShellBase.cxx    rev. 1.42.40.1
/sd/source/ui/framework/tools/FrameworkHelper.cxx    rev. 1.5.38.1

Please verify.

Verified in CWS.

Tested in DEV300_m23.