“The Chicago art establishment, from museums to galleries to artists, still seems shaken by what it perceived to be the failure this spring of its internationally known contemporary art fair.” In fact, Art Chicago has been gradually losing the interest of the international art community for years now, and the flurry of activity surrounding this weekend’s much-ballyhooed opening of the city’s new Millenium Park is meant in large part to put Chicago back on the map where art is concerned. Art Chicago’s organizers insist that a comeback is imminent, but observers are skeptical, especially as the fair prepares to move to temporary quarters in a 125,000-square foot tent.