The US Army will be withdrawing support for sustaining the AH-64D Apache Longbow's Block I standard by 2017, which poses a bit of an issue for the UK.
It's less than a decade since the British Army's Westland-completed Apache AH1s entered use (initial operating capability came in October 2004), but the service needs to act fast in deciding what to do (and, more importantly, getting its hands on the budget required) if it is to avoid footing the bill for future software development and so on.
UK Apache force commander Col Andrew Cash says a range of options are being considered, ranging from "do nothing" to even "an entirely new replacement attack helicopter". I think we can discount both of those, so his middle ground options: of some form of technology insertion (seemingly being offered by AgustaWestland); or a modification along the lines of the US Army's Block III AH-64E standard (presumably courtesy of Boeing), are more probable outcomes. We might get an idea from early next year, when an assessment phase activity should be launched.
Buying 67 AH-64Ds (Crown Copyright image above) and adapting them with some UK-unique equipment was an expensive route for the UK to go down a few years ago, but the type's strong performance in Afghanistan since May 2006 (using the callsign "Ugly") and also over Libya last year have more than vindicated its choice back then.
As we've seen with ongoing capability sustainment programmes being performed on UK types including the Royal Navy's AW101 Merlins and Royal Air Force Pumas, costly modernisation means fewer aircraft, so the Army Air Corps' AH fleet will shrink in number over time. But Cash says work will be done on honing its "find/strike" concept, alongside AgustaWestland's developmental Lynx Wildcat, so firepower won't necessarily drop.