Thanks for all the helpful replies. I suppose once you're airborne, you fly your normal V2+15 (if no windshear), but it just felt wrong on so many different levels to see the speed bugs arranged that way. Live and learn.
You also get "Windshear advisories in effect" at US airports, which I take to mean the system is working, not that there are actual windshear conditions present. I haven't been able to find a reference - does anyone know whether this is a correct interpretation?
You're pretty much right. Any major US airport almost always has windshear advisories in effect- a lot like the warning like birds in the vicinity of the airport.
Here's a tip. If there's a big black cloud over the airfield and you're worried about windshear or microbursts, keep an eye on the OAT guage. If it drops about 5 degrees all of a sudden, don't go. It's the cold air from a downdraught hitting the ground and spreading out. Not conduscive to safe aircraft operating!
Thanks for that tip Dan. While waiting out some wx the other day, the ATIS temp fell 3-4 degrees with an associated wind shift. I'll certainly keep that information handy.