TfL have a promo video of the new Routemaster bus.
From an aesthetic point of view, the rear aspect has echoes of the old routemaster, but from the front it looks rather like any other modern bus. From a practical point of view, it has the same capacity (87) as most modern buses, but a lot less than the 'bendy bus' (140-odd). However, it has 3 entrances so boarding should be quicker.
There was some concern about the accident record of bendy buses, which was one of Boris's justifications for getting rid of them. From a BBC report, "There was a 45 per cent rise in accidents involving the No38 Victoria to Clapton between April 2006 and the same month in 2007, the first full year of bendy buses, compared to the previous 12 months when double-deckers were the main vehicle on the route. Accidents rose by 70 from 154 in 2005/06 to 224 in 2006/07."
The Standard reported "bendy buses cause 5.6 pedestrian injuries per million miles operated, compared with 2.6 for all other buses. They are involved in 2.62 collisions with cyclists per million miles, compared with 0.97 for other buses. And they have 153 accidents per million miles, compared with only 87 per million on non-bendy routes."
However, I'd sound a note of caution here. First, the bendys cover the busiest routes, and likely roads with a higher density of pedestrians and cyclists, so it doesn't necessarily follow that the buses are wholly to blame. Second, the bendys have 50% higher capacity, so you need fewer of them. Because of that, accident rate per passenger mile is rather closer to non-articulated buses.
As a cyclist, I do not like the bendy buses. Any vehicle that long with a bend in the middle is going to be difficult to filter past and it must be difficult for the driver to monitor surrounding traffic properly, especially at night.
A second justification for scrapping the bendys was that there was a lot of fare dodging. The new Routemaster will have the same potential for fare-dodging, having 3 entrances, but will apparently have a conductor when the rear platform is open. The flaw in this scenario is that you could have a conductor on a bendy bus, and because of the higher passenger capacity of each bus, you would need fewer conductors per route.
So the New Routemaster does look rather more like a vanity project than a great leap forward. However, Boris is a master of presentation. If the new bus can make Londoners feel good about their city and encourage more people onto the bus network, maybe it's no bad thing.