NEW YORK—The auction houses must be breathing a sigh of relief after another round of solid sales, this week's Impressionist and Modern auctions in London, confirmed the art market’s strength. A Monet waterlily sold at Christie’s for a record ₤40,921,250 ($80,451,178). Meanwhile, across the pond, a painting donated to a Goodwill store in Maryland also turned out to be a pretty valuable Impressionist; it sold for $40,000 at Sotheby’s.

Is it or isn’t it? seems to be the question of the moment. A Goya at the Prado may not be a Goya after all. An El Greco just may be a portrait of the architect Palladio. The latest folks to find what they believe is a Jackson Pollock painting think a fingerprint could authenticate it, but the fingerprint itself might be fake. And a collector is suing Louis Vuitton over the failure of one of its fashion boutiques (um, the one that was inside LA MOCA for Takashi Murakami’s retrospective there) to follow proper California law when it sold the collector some Murakami prints. Without the right certification, the limited-edition prints might not be considered authentic. (So, maybe one shouldn’t buy art from a fashion store? Just a thought.)

An artist wants California to stop using his image of a whale’s tail on license plates, since the state never paid his foundation. Another artist’s floating banana may be forever grounded. R.E.M. lead singer Michael Stipe tried his hand at sculpture.

Ah, capitalism: Arts institutions occupying prime Moscow real estate may be in trouble if the state envisions profitable ventures on their land. Other art and real estate news was more promising: Key players in the London art world, including Tate Modern director Nicholas Serota, backed up painter Paula Rego’s attempt to defend the sunlight that comes through her studio windows from a proposed apartment building next door. And in news that gallerists are sure to be ambivalent about, plans were revealed for the tourist-drawing High Line Park in New York’s Chelsea art district.

The Guggenheim Bilbao plans to add a branch on the city outskirts, funded by local officials. Walker Art Center curator Philippe Vergne became the new director of the Dia art foundation. And critic Jed Perl has “not had much of anything to say after visiting a number of widely discussed events: the 2008 Whitney Biennial; the opening show at the New Museum of Contemporary Art (aptly titled ‘Unmonumental: The Object in the 21st Century’); the survey of Japanese artist Takashi Murakami at the Brooklyn Museum; the Olafur Eliasson show at the Museum of Modern Art; the exhibition of Jeff Koons's sculpture on the roof of the Metropolitan Museum of Art. I have had thoughts, sure; but they are the thoughts of an anthropologist rather than a museumgoer, of a student of the art world rather than a person who has had an encounter with a work of art.” Is it or isn’t it? Alas.