Arrow didn't actually go under / go out of business. When they were having their financial woes with SFMM and X, they were purchased by S&S Power of Utah. S&S Power also, like many of you know, hired Denise Dinn to create S&S's wooden coaster division after CCI going under. After the aquisition of Arrow Dynamics by S&S, they were for a moment called S&S-Arrow, but S&S later dropped the Arrow nametag and the future "Arrow" coasters will be under the S&S Worldwide nametag. S&S Worldwide is primarily known for their tower rides, and their compressed air technology, but they are now trying to make a name for themselves in the coaster business.
S&S / Arrow / Whatever You Wanna Call Them are currently perfecting the 4D coaster technology, along with developing new coasters that will use S&S's compressed air launch technology. While the name "Arrow" will no longer be around, new "Arrow" coasters will be still popping up in future.