"domain through arbitration"
No such thing as "arbitration". There is filing a UDRP though. Or a cybersquatting lawsuit (non-starter just mentioning).
"selling TapTyping on the App Store since the iPad came out almost 2 years"
Because the domain was registered 6/2008, off the top without researching all the facts, you don't have a case from my experience. And filing will cost you (through http://www.adrforum.com) $1300 for 1 panelist and $2600 for 3 panelists. You can do this yourself but I wouldn't recommend going that route. There are other forums but last I checked adrforum.com is the most pro complainant as well as the least expensive (check, that may have changed but you won't find it for $9.95 or anything..). So if you need a lawyer to handle you need someone who specializes in this (you can write to me for suggestions). The cost for that is going to be in addition. That's if they take the case at all. The best ones might not take the case if they don't feel they will win because it will hurt their win rate.
"The current owner has yet to do anything with the domain. It is just Godaddy parked."
Of course as you know that doesn't mean anything. No requirement to use a domain name.
"he simply replies that he "is not ready to sell the domain at this time""
Could be true, or could be a standard reply to get you to offer up some money and obviously (to me that is) not jeopardize any future proceeding. Saying you will sell can be used against you.
"but even once the trademark clears is this an open and shut low risk case"
Not at all.
The advantage of filing is that the other person has to defend. That means they have to spend money and time. If the name isn't important they might just ignore the filing. In some cases when the filing is ignored the complainant gets the name by default. But not in every case. Sometimes the panelist(s) don't do that. Or they might reply, not use a lawyer, make a mistake and you might get the name.
My research indicates this is the guy that owns it (there are many Jeff Merediths but I believe this is the one based on the mit.edu and his linkedin)
http://www.linkedin.com/pub/jeffrey-meredith/19/b35/b2
How much money is the domain worth to you at this point? What you are willing to spend determines strategy.