Do the new Macbook Pro 13"...

As the aluminium is better at conducting heat, the laptop will feel warmer than the white/black poly-carbonite MacBook.

Btw, if you run CPU intensive tasks, and viewing Flash content is CPU intensive, the MacBook will get warmer. You could disable Flash via ClickToFlash.

 

I use lightroom and cs5 on mine and it's not too bad

rendering in final cut is another story temp wise

 

Operating temps. All temps in Celcius with fan speed at 2000rpm:

Nothing running/all apps closed: 37 degrees
Running Safari with Flash webpage: 60 degrees
Running Safari with Flash and video: up to 80 degrees

As it gets hotter, I use SMCfancontrol to boost fan rpm's to compensate.

 

Depending on what tasks you perform, the CPU might be taxed or might be not. Lightroom uses a lot of CPU though, especially during Preview renderings. If the fan is correctly set, you can remedy the heat.

 

Playing a flash video on my laptop can make the laptop go to 80C but doesnt feel nearly as hot as my dell that never got past 40-50c

 

Ive had my 13" since the start of the month and in terms of heat all i can say is its great. It certainly in my experiences on my lap doesnt get warm during safari browsing the internet via it being flash content or playing 1080p video. The feeling of the notebook again doesnt even get hot when playing the Sims 3 mac version at high detail setting for numerous hours. So i wouldnt worry about it if i was you, its a great purchase the only time i have noticed a little heat increase is whilst in bootcamp running Windows 7 and playing Call of Duty modern warfare 2 at medium settings for about an hour, again it was still considerably cooler than my previous Samsung R505 laptop which was constantly hot.