This is not the original charger from Dell as it has a 2 pin power lead connector whilst the original has 3. Also, there is a circle on the top of the original charger which has 'DELL' inscribed on it whereas the circle on this charger has been left blank.
However this charger does the job, and for the price, you would not be expecting an original anyway.
I was a bit sceptical at first, cos I had previously bought one of these chargers from ebay (same blank circle on top, 2 pin connector etc), and that charger worked for a while, but then affected my mouse pad so that the mouse would not move freely, and when I moved it to a particular spot (say the button/cross on the top right corner to close a page) the mouse pointer would keep shaking and quivering so that sometimes by the time I clicked, it would have have moved to one of the other buttons (eg the minimise button).
I only received this charger yesterday, but it does not cause any of the problems mentioned above that I had with my previous charger. I will post an update if it starts to mess around, but for now, it's 5 stars for doing the job it is supposed to be doing!!
Update on 12 May 2011
Charger is still working without any issues (almost 2 months on), so the 5 star rating remains.