It's the penultimate day of Propellerhead's five-day run of announcements for Reason 5 and Record 1.5, and today they've revealed that all sample players in Reason 5 will function as - yes! - proper samplers. You'll thus be able to record audio straight into them, just like old school hardware samplers.
So, sampler modules like NN-XT will be able to record audio from an external source like a microphone, or indeed, from any sound source inside Reason itself - you just need to hook it up to the rack's sampling input and hit the record button. Reason will automatically detect where the sound starts, so you don't have to fiddle about setting the start point by hand, although you can do this - and much more - via the integrated sample editor.
Sampling can be done on the fly, even while your project is playing, which should ensure that the flow of creative juices is not stemmed. There's also pitch detection and automatic zone mapping, which Propellerhead say will allow you to resample instruments (eg, a Thor patch plumbed through loads of effects) and turn them into multisampled patches. Very cool!