If all you edit with Premiere Pro is SD (Standard Definition) you should be able to edit... for HD, not so much
Some ideas for a Laptop Video Editing PC from past discussions
-or Google "ASUS G74SX-BBK7" (without the quote "" marks)
For effective HD video editing, a laptop with the following
-the newer Intel sandy bridge 2720 or 2820 quad processor
-and nvidia graphics preferably the 460m, 485m is a bit much
-1280x900 display with OpenGL 2.0-compatible graphics card
-and 8 or 16 gig ram and Win7 64bit Pro
-and 2 internal 7200 HDDs minimum
This message has a really good graphic about requirements
CS5 Requirements http://forums.adobe.com/thread/810750
About Requirements http://forums.adobe.com/thread/618058
Disk Configurations http://forums.adobe.com/thread/878419
I'm only speaking for Premiere Pro CS5.5. That laptop will run it - but its performance will be rather sluggish, on the order of about 20 to 25 times slower than a fast hexa-core i7 desktop. The biggest drawback is, as you stated, the integrated Intel HD Graphics: It cannot use MPE's GPU acceleration at all. In fact, only NVIDIA GPUs with CUDA support can use MPE GPU acceleration at all in CS5.5. At least that laptop has a quad-core Sandy Bridge i7 CPU (the i7-2670QM, in this case), and you can replace the existing 8GB of RAM with a new 16GB SO-DIMM kit. Plus, its display just meets the minimum vertical resolution of 900 pixels (screen resolution: 1600x900) required for PPro CS5.5 to display properly.
Other drawbacks include only a single hard drive although you can add up to two USB 3.0 external hard drives to that laptop.
In addition to Randall's comments, have a look at: Adobe Forums: System requirements for CS5
It depends on the material you will edit. For simple codecs and the addition of two USB3 disks, it will be OK, but with difficult codecs you will be frustrated very quickly by the sluggish response and the extremely long export times. Remember, if a fast desktop needs around one hour for exporting a timeline, this system may require 24 hours for the same timeline, as Randall described.