Matilda Battersby: I fear time has caught up with the thin white duke

I once offended someone famous by asking how it felt to be a national treasure. My (admittedly rather limp) line of questioning was met with an alarmed, and evidently miffed, response from an interviewee who said she didn't see herself that way.

I was reminded of this while listening to David Bowie's (brilliant) first single in a decade "Where Are We Now?", released yesterday morning. Its nostalgic, mellow feel, describing the glam godfather's days raving in Berlin with Iggy Pop, and – most markedly – its arrival on his 66th birthday, seem like an admittance of his modern icon status. He might always have avoided the mould, ch-ch-ch-changing the boundaries of sound, style and form beyond recognition. But yesterday Bowie admitted to being the equivalent of a national treasure. Welcome though the new song may be, the echoing dreaminess of "Space Oddity" it invokes feels a bit backwards. Especially as the release of his new album, The Next Day, in March coincides with the opening of a major exhibition called "David Bowie Is" at the Victoria and Albert Museum.

Ziggy Stardust may have retired way back in 1973, but I doubt fans will stand for the signal that this double retrospective sends: that Bowie is re-evaluating his career, perhaps in readiness, to put it away for good. Particularly when similarly mummified Seventies rock gods The Rolling Stones are determined to put him to shame by rocking on till death (and raking in £20m per tour in the process).

For an artist who has always shunned the PR bandwagon (preferring rockets), the non-coincidental arrival of an exhibition and album in the same month feels rather manufactured. The former is a testament to how present Bowie has remained in British art culture despite the fact he has appeared in public, and on stage, only a handful of times since his heart attack at the Hurricane festival in Scheessel, Germany, in 2004 – collapsing just minutes after performing an encore of "Ziggy Stardust". Bowie refused to promote last year's 40th anniversary reissue CD of The Rise and Fall of Ziggy Stardust and the Spiders From Mars and even declined a personal plea from Danny Boyle to appear at the Olympics opening ceremony, so I'm pleased that his return to view is to promote new music.

But his decision not to move things on, as he has always done (from Mod to mime artist and folk singer to R'n'B musician) rings alarm bells. Time has changed him. I hope the new album is not all about tracing it.