I did come up with a bit of a workaround when you want to type a full path, however. Suppose you want to enter '/usr/bin/gvim' in the file chooser--since it's much faster to just type it than click, click, scroll, click all over the filesystem to find the file, but I digress--you can type 'gvim', then put the cursor at the beginning of the input field and type '/usr/bin/'. This prevents Gnome (or GTK+??) from destroying your input.
The Perl foundation's move to Git took so long primarily because they had to gather decades of history from scattered sources: "Some of the patch sets were apparently recovered from old hard drives".
For instance, the MySQL project moved to Bazaar last year, apparently very smoothly. Getting started with Bazaar for MySQL.
Anyone can make an omelet with eggs. The trick is to make one with none.