Interestingly, this feature that was once part of the Gmail Apps Search experiment in the Labs section, has now been graduated. As such, suggestions are now being offered whenever you perform a search.
In fact, Gmail has a little ways to go in catching up to Google in search capability, as Google Operating System points out — just an option for relevancy sorting would be nice. This one is rather simple, but nonetheless it would be generally welcomed by every user, as the mind that can sometimes move faster than the fingers.
Anyway, it is nice to see that Google is working to enhance Gmail search, though as Alex Chitu points out at Google OS, there is still plenty of room for improvement. The best part is that you do not have to do anything to enable this, although some Gmail users may have already had this (because of the Gmail Labs).
Moreover, moving ahead Gmail users will see a “Did you mean” style suggestion which will offer a correctly spelled version of what you tried to search for. And as you can see in the above image, it offers both the search results as well as the option to click on the “did you mean” word or term. So the choice is yours.
Finally, for those who have never really toyed with the Labs section in Gmail — there is a ton you can add in terms of functionality. Not necessarily dealing with search, but you can do things like add a Google Calendar or Google Docs gadget to your sidebar, have your Google Voice messages play directly in the message, move the chat to the right side of the message window and much more.