Yes, it is highly likely that the non-hotel center-Strip casino, which opened in 1989, will be closing soon. No official date has been announced as yet, nor details of exactly what the change will imply (there has even been talk of "relocating" the casino), but we've heard sometime in February of next year will likely see it closing in its current incarnation (although tickets for resident headliner Dirk Arthur's magic show are still available until March 31).
Ever since Caesars Entertainment first announced its plans back in 2009 for what was originally called Project Linq, a massive pedestrianized retail, dining, and entertainment complex for its center-Strip land block, the future of the old casinos that occupy that strip of the Strip has been in question. While the Flamingo and IP will apparently receive major facelifts as part of the remodel, O'Sheas did not fare so well and has been scheduled for demolition, although not implosion, as far as we know.
Although it lacks a hotel, O'Sheas managed to carve out an identity for itself as a party place in recent years. Home to one of the original in-casino tattoo studios, owned by wild man Vince Neil, it's also an official Beer Pong tournament stop, a perennial favorite for St Patrick's Day celebrations, and home to a Havana Cigar venue (we can't describe it as a "lounge" -- it's really more of a booth!)
A major remodel of the Flamingo's rooms and public areas is already underway, but few details have been released as yet describing what's in store for the IP in its new incarnation, or O'Sheas. All we know is that The Linq is expected to feature 30 to 40 new retail, dining, and entertainment attractions, including a massive observation wheel, in what's being described as a 200,000-square-foot open-air marketplace (presumably complemented by and integrated with the surrounding casinos and hotels).