I have a 2010 R350 and recently the vehicle has started flashing the triangle with the exclamation point in it. It's the ESP (Electronic Stability Program) I believe.

This is in Florida. Roads are completely dry when this is happening. It's not due to ice, snow, or rain.

This only seems to happen when the wheels are turned to the right. Not to the left.

This only seems to happen at highway speeds (at least 45 mph) and I don't notice it at lower speeds.

This seems to happen as the car shifts (but it might just be the engine governing itself that I feel as the warning pops up).

The light flashes a few times, cruise control turns off, and a message about the cruise control pops up if I recall correctly.

I feel as if it's a wheel speed or slippage sensor, but I'm not 100% certain.

Am I correct that it's a front sensor? And which side would this be? And where are these sensors located? And, what is a part number?

It could be the ABS sensor as you suggest. The plastic brackets holding them in place break easily, and then the wire rubs against the axle on the front. Crank the steering wheel all the way to the left and you can look in there to inspect and/or replace the driver side sensor. Same deal for the passenger side except crank the wheel to the right.

Even a sensor that looks okay visually, may be broken/defective. Some scanners will tell you which sensor is faulty, such as the iCarSoft i980, but only if there is a stored error or if the sensor is currently malfunctioning (pardon the pun).

Other culprits:
1) out of alignment
2) uneven tire pressure
3) uneven tire wear
4) misaligned steering sensor
5) worn tie rod ends

I did notice uneven wear on the outsides on one of the front tires the last time I checked. I'll look at that again when I'm at the car next time.

Well, I checked over the tires again and they look fairly normal. A few more details about this situation:

The iCarsoft i980 pulls a code of:
7266 Speedtronic Occasionally Nonfunctional
and
5173 Steering Wheel Angle: Signal Fault

I'm also getting:
11B00 Component NOx sensor Upstream of SCR Catalytic Converter has a Plausibility Error, but I'm 99.999% sure this is unrelated. Just including that in the very off-chance that it's related.

For the last 2 weeks or so, the steering wheel has to be to the left slightly when driving straight. If the wheel is turned straight, the car pulls to the right.

Oh, and I lifted the front end yesterday, one side at a time, and checked for excess slop in the front end. I don't know what qualifies as excess, but I don't feel as if it's worn out.