As tempting as it is, I don't think Ahsoka should ever go live. She exists as a very popular cartoon character, and may even fit the 'Disney Princess' mould better than Leia. That's not something they're going to want to tamper with too much. My guess is if you ever see a live action Ahsoka, your probably walking around a Disney theme park.
The Togruta's average life expectancy is 94 according to Wookieepedia, which is above real-world early-21st-century human life expectancy, but a bit below the life expectancy of Star Wars humans. Ahsoka was born c. 36 BBY (i.e. before the events of the original movie), and Return of the Jedi takes place in 4 ABY. So if Episode VII is c. 30 years after ROTJ, then Ahsoka would be c. 70 at that time.
Hell, Ernie Hudson played Winston in the live-action Ghostbusters movies and lost out to Arsenio Hall to play him in the animated series.
Sorry to disappoint but that particular picture of her on deviant art isn't canon unless there's another reason why her nickname is "Snips".
Are you guys aware that Ashley Eckstein did a cosplay as Ahsoka for a photo shoot last year? Ashley as Ahsoka
Yep. My suggestion that they cast her took that into consideration. She has the same level of resemblance to the cartoon character as Ewan McGregor does to Sir Alec Guinness, meaning close enough. Plus, there's always the magic of CGI that could play a factor. Naturally, Ashley sounds exactly like Ahsoka for some "puzzling" reason. Of course, all this would be pending auditions, etc., not to mention we don't even know whether there are any live action Ahsoka adventures in the pipeline. Another possibility, that I'm sure they'd consider, is they might split the difference, and use a different actor for the physical stuff, but still call Ashely back to do the voice. They might even try to Jar Jar her, that is more than just simply tweak the physical actor's basic appearance.
^ Well, that's just hideous looking. Obviously, the quick-and-dirty execution has something to do with that.
What's weird is that, despite the train wreck, it did sorta work. It proves that the idea might work, but it would have to be attempted seriously to really know. And it would be hard to avoid dropping off into a deep uncanny valley.
It does inspire one to see if there might be a less trainwreck-y possible way to do it: 175% eyes and a slightly reshaped skull to accommodate them. Eh. It's serviceable.