This is useful when you are looking for targets / machines provided by a certain layer, since you can type the layer name to get a list.
We'll try making the summary and description information searchable instead.
Pushed for review on http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/log/?h=adamian/20150309_bugz
merged in master
It looks like this is working for targets, but not for machines.
This has been fixed by the new type ahead widget (bug 7152)
Verified on jethro: fc45deac89ef63ca1c44e763c38ced7dfd72cbe1