What are your goals when it comes to getting a new laptop? If your concern is portability(read thinness) and/or battery life, newer systems are exceptional. If you concern is performance, I wouldn't worry much about CPU performance so much as disk performance unless you're gaming or doing a lot of encoding. Even then, encoding usually isn't time sensitive. Know your needs first and foremost.
I'm using a 2450 to write this. The laptop I'm using it on seems quite zippy. Both with a harddrive and with an SSD(especially with the SSD). The laptops I've used in the past included a 1.1Ghz ULV celeron, a 1.8GHz i3 based cereron and this. Desktop side, I've had a Phenom II @ 3.4 Ghz, a c2d e6400 @ 3.7 Ghz. At work, I use a a p8600 system. The main deficiency with my work system seems to be a lack of RAM(only 2GB). I primary do statistical analysis, and it only really chugs while doing analysis on huge data sets, or while doing large, complex time series calculations with many autogregressive terms. I'm hoping that when I get THIS(http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c02057761&lang=en&cc=us&taskId=101&prodSeriesId=4138087&prodTypeId=321957
) in the mail that it'll resolve any issues I'm having(16GB RAM is a blessing, as is the quad core CPU)
While I'll say that CPU performance doesn't matter as much as most think, I certainly will say that I can feel a difference between this and the 1.8GHz celeron system. It could partially be due to disk performance however. Additionally, the graphics performance(Intel 3000+ Radeon 6650) probably help out as well.
Try swapping an SSD into your current laptop first and see if it makes a difference. If you're unsatisfied, take the SSD with you to a new laptop.Edited by xlink - 11/6/12 at 10:57am