Real quick, for the dummies on here (Me), what are the advantages of ICS?
Honestly, most of the big ones we already have (at the front end, at least). We already have some of the front end features of ICS (camera access from the lockscreen, quick shutter, panorama mode, folder creation, resizable widgets; a few others). The ones we'll get that we don't already have are Face Unlock (unlock the phone with your face via the front facing camera), a better hunt-n-peck keyboard (I'm a Swype acolyte for sure, though), better multitasking pane (a la Honeycomb style), more integrated themes (it won't get rid of Motorola's themes, but more apps should start to come out that will match your stock theme); some other stuff I'm sure I'm forgetting. It'll basically be a nice UI overhaul on the front end.
On the back end, though, Android always improves it's speed, garbage collection, multitasking, etc. in every version. Your RAZR should be snappier, battery should last longer, etc.
As for Blur updates, we won't know until we see them. Blur used to suck, but this last version is actually quite nice. I have to say I'm rather looking forward to Motorola's rendition of ICS.