The firm administrating the shut down of Realtime Worlds says (via Eurogamer), "customers should revert to the entity from which they bought the game in respect of their entitlement to any refund." Steam will not be offering any refunds, explaining, "as with most software products, we do not offer refunds or exchanges for purchases made online as outlined in the software license."
Some users on the Steam forums, however, have had luck in getting Electronic Arts to fork over discount coupons or even free games. This is being done on a case-by-case basis through EA support, but owners interested in any compensation should read up on how people are getting hand outs.
While the retail version of the game shipped with 50 hours of playtime in the game's action districts, many players may not have put in that much time. As is the case with any online-only title, situations like this can and do happen. Exercise caution when shelling out money up front for these types of games. Anyone sitting on a Hellgate: London lifetime subscription? Exactly.