Eclipse 3.5 is out in the wild for some days now and as always I downloaded the newest version as fast as possible. After installing the first plugins I was struggling with the following problem when I wanted to change the embedded maven to my installed version under the directory /usr/local/maven on my MacBook Pro.
In the former version of Eclipse (3.4.2) which I’m using in my daily business it was no problem to select in this directory in the dialog which is popping up when you select in the eclipse preferences maven->installations->add.
It looks like this – the folder /usr/local/maven is accessible by clicking on it
But when I do the same with Eclipse 3.5 I get the following dialog
A lot of directories does not appear anymore… 
after searching a lot I found the really simple solution…
Just click on „new folder“ („neuer Ordner“ in german) then you get a new little dialog where you can enter the path to your maven installation by hand… in my case /usr/local/maven… If you start typing in this dialog the little dialog switches again to an other dialog which is shown in the next screenshot (titled switch to folder/gehe zu Ordner)
If you klick start you get the following result… the dialog is now in your directory you wanted to select and you can select it at the end 
I checked this behavior with other dialogs in the Eclipse 3.5 preferences like Java->Code Style->Code Templates->Import… There it’s also not possible to navigate like in the dialog in Eclipse 3.4.2
So I hope this saves someone a bit of searching time
13. Juli 2009 um 19:00
I found a second quick solution. By using the key combination ‘cmd+shift+G’ you can also enter the path to the folder you which you want to select.