I am actually pretty angry about the changes to gnome stats in 3e. In 2e, at least in the complete guide to gnomes & halflings (I was my group's official 'lover of the little people'), gnomes were described as extraordinarily strong for their size, and that was the reason they didn't get the str penalty (something which I've seen backed up in other fantasy sources). The int was because they were smart and good with illusions, and int was the spellcasting stat for wizards in 2e, and the wis was because they were pretty foolish and their pranks would backfire or have unintended results (as a result of them not planning far enough ahead, etc. etc.). The reason these stat mods were changed for 3e is because wizards seems to have had a problem with giving any PHB races a bonus to mental stats (though they also state that bonuses to mental stats are supposedly weaker then bonuses to physical stats, so if the reason was because they were concerned about overpowering pc races then they're just a bunch of hypocrites). Also, str -2 is standard for almost all small size creatures, and I suppose they gave the con bonus just so they could give gnomes a different stat mod than halflings got. The rest of the gnome abilities I don't mind much, but I really think they screwed up big time when they switched the stat mods. Personally, if anyone ever tries to play a gnome in my campaign, I am going to use the old stat mods...and I refuse to play a gnome myself with the 3e mods too.
On a side note, that arcane gnome doesn't sound too bad...the +2 con (and the -2 str, sort of) is still a mystery though.