$3000-$4000 to spend on a new bike

2008 Specialized Transition Pro.  I just bought her for $4,000. 

curious?, what makes it a her versus a he?

I go with everyone else who sugget spliting up your money.  Either get a bike and power meter or bike and wheels.  No need to drop $4K in 1 place. 

As far as which bike to get that is hard to say.  Any bike you spend that much money on is going to be a nice bike.  It is more a matter of how it fits you, not how much someone else like it.  Remember we are talking about bikes not cars,  they are going to have a different feel for everyone.  An inch different in one measurement could mean the world to one person.  I would suggest trying bikes until you find a few you like and then ask around to see if people have a preference.  If you find one bike that fits perfect buy it and don't even ask.

Because with that bike you'll get lots of T.I.T.S. ?

X2... was reading reviews of tri-bikes the other day, and this (rough) quote stuck in my mind... "the smart money spends $2500 on the bike and uses the rest for a power meter, aero helmet, etc..." 

I would go with something a little less expensive than that, and then also get a power meter. But, that's just me.

I officially hate you .

(Well, not really, but I LOVE that bike.)

x2 

Mid 2's you can get a carbon frame bike with ultegra parts and there are lots to choose from...get the one that fits you best that is red ; spend the additional on a coach for a year or a power meter. I think with PM or coach you'll be faster in year than with a more expensive bike.

Planet X

Bike 18 - Black Pimp Stealth - Medium

Built for the RTTC 2008 handbook photo shoot.
Brand New - Never ridden

Pimp Spec

Stealth Pro Carbon Frame, Fork and post - size large
Dura Ace mechs, cassette, chain, brakes and shifters
Planet-X Pro Carbon 82 front, 101 rear tubular wheelset
Planet-X Stealth bars

RRP - £2099

I have no personal experience with Planet X but it looks like you can get a lot of bike for your $$, or pounds, I'm not sure what the exchange rate is but somewhere between 1.5 to 2.

Just checked it's hit a 26 year high exchange rate is 1 pound = 2.0579 dollars. WOW

My $4000 got me a QR Lucero and a membership in the "Black Legion of Doom" bike club which destroys all RED bikes on race day

With $4000 you can buy whatever you want.  For instance you could get a  Specialized Transition Pro for $4000, a  Kestrel Airfoil Ultegra for $3999, a  Guru Chrono Ultegra for $3900,  Kuota Kalibur for $3900.  Or you could buy a  Quintana Roo Lucero Ultegra for $3300 or a  Felt B2 Carbon for $3300 and have some money left over for an aero helmet and a wetsuit.