Good question, Gordon.
I also wonder if, despite it seeming all-but-quixotic and certainly non-considerable right now, the stretch of highway between Fort Smith and Texarkana will in a few years, quicker than we think, itself be called "the most important project in southwest Arkansas". Or maybe Arkansas proper.

I'm reminded, for anyone who remembers it, of when the Larry Johnson/Stacy Augmon-led undefeated UNLV basketball team (fresh off a national championship season, going undefeated until a loss to Christian Laettner/Bobby Hurley-led Duke in the NCAA semis, with all five UNLV players making "all-American" and being called "the greatest team to never win a national championship") came to Arkansas (which itself only had one loss and had perhaps its most heralded recruiting class to date playing as seniors, who set the table for back-to-back national championship games a few years later, winning one of them). At the time, UNLV was #1 in the polls, Arkansas #2.
Larry Johnson couldn't get into SMU academically in his hometown of Dallas, but he was smart enough in a pre-Arkansas game interview, when told that someone (Dick Vitale?) had predicted UNLV to lose, to respond: "Hey, he's pretty good. He's usually right." In reality, Dick Vitale, in the UNLV/UA pregame, said "The UNLV players are
sky-high about this game". And they were, blowing out Arkansas on the latter's home court.
Promise not to use this Texas DOT map above (reprinted on video recently by KTBS-TV Channel 3/Shreveport) again, but the fact that the
Texas DOT did this map, and that key to it is I-49/Arkansas, tells me that secretly, behind the scenes, there are some important people
sky-high about a prospect of a completed I-49. And again,
given the fact that the possible chief I-49(/I-69) beneficiary Houston is now America's #1 goods port also tells me that some of these sky-high players may have some very deep pockets. Don't get me wrong, they won't spend their own money to build an interstate through the Ouachitas. But they can make a LOT of noise about it. And sometimes that's all it takes.
This will get interesting in the Natural State. Many of us expecting otherwise may even live to see it...
(EDIT: hadn't ever looked it up, but Wiki says stats show the ports of South Louisiana and Houston were ranked #1 and 2, with the NYC/NJ port #3. Beaumont is
#4! Meanwhile, Duluth/Superior (#18 in the US) Port's website says
this port is the #1 volume port on the Great lakes, #2 in dry bulk in the U.S. (though I'm guessing much of that is grain which wouldn't head down the I-49 corridor).
http://en.wikipedia.org/wiki/List_of_North_American_ports#United_StatesThis tells us so much of we need to know about I-49/I-69.)