I've heard nothing. The better question would be why would they WANT to buy Hasbro? Hasbro has licenses with both Star Wars and Marvel. Cutting that off (in a sense) would mean a significant drop in profits I'd think. You could say they would then own all of Hasbro's IP's, but if Battleship has taught us anything, it is that those board game movies may not pan out. On the other hand....My Little Pony, Littlest Pet Shop and Strawberry Shortcake would add more girl power to their stable...Playskool would provide their own mast head under which they could unleash all their own Disney toys...and there's the little license called Transformers to reboot in films and license to the planet.
Now if you want a collector's standpoint, it could potentially be excellent. Not having to pay for licensing for SW and Marvel SHOULD mean reduced prices across the board (which probably wouldn't happen even if they could), BUT they could take more chances with items like vehicles, playsets and other products that are costly to develop. When you cut out the significant licensing fee, there's a lot more they could do (coughdeathstarplaysetcough).
Today, we actually put feelers out across the globe and it wasn't long before one tentacle was tingling with the power of KNOWLEDGE!! We can now report, with a good amount of certainty (but of course can not 100% confirm it as no one will go on the record) that Disney IS indeed in talks with Hasbro. That's it so far..talks..leading to a sale most likely...but of course anything could happen, so take it all with a grain of salt. Keep checking back and when we get an update, you'll know all about it!