Before I begin I have a confession to make. I have been playing Dungeons & Dragons in one form or another for nearly thirty years. In that time I have played nearly every conceivable combination of race and class.
Or at least I never remember having played one. So it is probably not too surprising that my reaction to the announcement of gnomes not being in the Fourth Edition Player's Handbook was one of extreme indifference.
I think the problem with gnomes is that they lack what we in the corporate world would call a "strong brand identity". This probably dates all the way back to First Edition. All of the playable races in 1st Edition except gnomes had roots in J.R.R. Tolkien's Lord of the Rings trilogy. Not that dwarves and elves didn't exist before the Lord of the Rings, but the versions of them that were presented in the Player's Handbook were certainly influenced by it. I believe this strong connection between early D&D and Tolkien's work helped develop the brand identity of these races in D&D.
Gnomes didn't have this help and it shows. In First Edition the gnomish racial abilities were basically a mixture of half of the dwarven racial abilities and half of the halfling racial abilities. Unique to gnomes were that they were good illusionists and they could speak with burrowing mammals.
Speak with burrowing mammals? Seriously?
Second Edition hurt the gnomes even more by turning the illusionist into just one option among many for specializing your wizard. So instead of being the best practitioners of a mysterious class with unique spells, they were really good at one subtype of magic-user. Third Edition kept this same dynamic, but 3.5 tried to spice things up by giving gnomes bard as a favored class.
Let me say that again. To encourage people to play gnomes they tied them in with the bard. I think that speaks for itself.
Nevertheless, I know people who love gnomes. Thinking back, the lack of strong branding was a selling point for these players. Want your gnome to replace every third word with "Gnome" the same way the Smurfs do with Smurf? Who the gnome am I to gainsay you! Want your gnome to have eight page long names and talk a mile a minute just like a gnome from Krynn? Why not?
I am sure that gnomes are not gone from D&D forever. The will probably make a comeback in Player's Handbook 2 along side the monk. When they return, I will welcome them back with open arms. I just hope that when they return that the designers have figured out who they are supposed to be.