Antonio,
There is no comparison.
1) The iPad mini is actually a shrunken iPad 2 with 16GB of storage. It has a 7" screen. The Dell is a 10.1 inch monitor with the latest technology.
2) The iPad mini can only run limited apps ... great for play and reading ( inside ... can't see the display outside ). The Dell runs full Windows 8 PRO ... so it has far more versatility on the apps and can actually work for business.
3) The iPad mini does not have a dock, the Dell does, which means easy charging and total connectivity !
My point is that a retail price of $ 499 ( and you can bet there will be some discounting ) is very competitive ... and this is only the FIRST tablet in this arena.
Of course, I enjoyed the full iPad ... but I sold mine to my grandson who needed it for school. Now I'm using my Samsung Series 7 Slate ... which is also running Win 8 PRO. It was a gift from Microsoft for attending a FREE developers conference in the area.
Tim