A slime mould with pale pink cylindrical sporangia on stalks, probably Stemonitopsis typhina (=Comatrichia typhoides). The sporangia of this species start out as white but rapidly (within only a day or two) turn pink, then brown and black. For some of the same species that I saw last year, see here.
This is what the spores looked like at x600 under the microscope:
First photo taken in the Wilderness, Whiteknights Park, Reading, UK, on 2012-05-11.