Well, lets list some of the most visible for 10.1 development: Garry Ekker and Stanislav Brabec, GNOME packagers. Robert Love, NetworkManager... You like it in 10.1, right? Larry Ewing, f-spot ... working nicely. Aaron Bockover, banshee ... working nicely and greatly enhanced for 10.1. Jeffrey Steadfast, gnome-volume-manager ... greatly enhanced for 10.1. Michael Meeks, OpenOffice_org ... nuff said. Joe Shaw, beagle. You wisely left out "working nicely" for NetworkManager and beagle.
Work perfectly for me.
That's actually one of the problems of most GNOME projects. NIH leads to dozens of (re)implementations which are shipped once they somehow work (for varying definitions of "work") and, regardless of their brokenness, they replace old, working solutions.
Total rubbush; Beagle doesn't replace anything, nothing provided equivalent functionality before. Not even close. Anyone who thinks it replaces 'find file' has clearly never actually used Beagle.