Today's releases from TNA (so far Madison Rayne, Crimson, Taeler Hendrix, Joey Ryan and Christian York) have been due to budget cuts within the company. The talents released were being paid a monthly guarantee with an additional fee when booked for TNA events. Since they weren't being used regularly, there was no need to have them under contract. It simply doesn't make any sense to pay people who are rarely being used and that the company has no current plans for. This is the same thing that happens almost yearly in WWE - they cut the "dead weight" backstage as it doesn't make sense to pay people who aren't being used.
TNA is talking of cutting more costs with the added expenses of producing iMPACT! on the road. This includes the exists of several executives in marketing and public relations.