To answer the title, no there's not an official race like that. I'd bet there's at least one third party write up though.
As to your actual post: it might not be too difficult to whip up an attempt. If I had my ARG here at work, I'd take a try at it. I'll look tomarrow, if I can remember.
The ARG is in the PRD. So if you want to try your hand at putting something together along the lines of an Aasimar or Tiefling, give it a shot!
I would want a Lawful one and a chaos one, or maybe a generic outsider race, with variants allowing for specifics.
To some extent, Fetchlings and Ifrits, Oreads, Sylphs, Undines.
All come from a neutral'ish stock and are native outsides.
Ok, here's an attempt at a half-Valkyrie.
The offspring of a Valkyrie and a mortal man, most of these children are left in the care of their fathers or as foundlings. The majority are female, but males are not unknown. They generally have regal features, a proud bearing, and a love of combat. Their most striking visual feature are their eyes, which seem to flash with tiny flickers of lightning, increasing in intensity as they become excited or angry.
Like their mothers, their otherworldly sight allows them to see who is near death. They are often comfortable in a saddle as well, frequently found on horseback. Those rare few who are lucky or skillful may even have a Pegasus mount, akin to their mothers.
Type: Outsider (native) Size: Medium Speed: 30'
+2Str, +2Cha
Darkvision 60' Constant: Deathwatch
Resist Cold and Electricity 5
+2 Racial bonus to Ride skill
Ride and Handle Animal are always considered class skills
Languages Common, Celestial. Bonus: Auran, Aquan, Ignan, Terran, Infernal, Abyssal, Draconic.
A 14 point race.
Little Red Goblin Games published a Xaoling rece -- it is a chaos-based native outsider race. WotC also had its lawful and chaotic planetouched races.
From Paizo itself, you could always go with the peri-born aasimar. Since they are descended from fallen angels, they cannot be readily pigeonholed as aligned with good or evil.
For a more general answer to the thread title- no, since there are few unified classifications of outsiders which are 'neutral'. Their themes just do not mesh well enough.
You get tieflings and aasimar since they each come a strong alignment spectrum. Things like ifrit also get by since they are born from all the 'fire' creatures, giving an extremely clear theme.
But can we name some neutral outsiders for a bit? Axiomites (living math equations), inevitables (axiomite's robot army), psychopomps (skeleton-y things), proteans (snakes with a shapeshifting and uncontrollable bent), and aeons (weird creatures symbolizing dualistic abstract concepts).
This is a lot harder than 'he has devil horns', 'he has feathery wings', or 'he has fire for hair'.
Little Red Goblin Games published a Xaoling rece -- it is a chaos-based native outsider race.
That one was by Rogue Genius Games actually (I wrote it).
Ok, here's an attempt at a half-Valkyrie.
** spoiler omitted **
Very cool, and pretty close to what I was thinking - thanks!
No worries. I might use them myself in a game sometime.