I have the exact same laptop but with the 720p 1366x768 screen.
The beta runs at about 60 fps on lowest setting and native res. You won't get good performance with your 1080p screen so I suggest playing at 1368x768, the nvidia 525m is a good little mobile card, but it does get a bit stressed when there is a lot going on the screen.
Dont forget the lastest nvidia drivers, they make a noticable difference in performance.
Thanks Enkep, this was really helpful
Is weird I thought they would be much higher O.o...
My Laptop:
Model: Dell XPS 15
CPU: Intel® Core™ i5-2410M CPU @ 2.30GHz
OS: Windows 7 64 bits
Display: 15,6", 1080p R+GB LED
RAM: 8 GB DDR3 1333 Mhz
Video Card: NVIDIA® GeForce GT 525M
HDD: Segate 500 GB 7200rpm
Thanks in advance