I brought a new DELL Inspiron 5220. It's amazing!
Configuration :
  • 3rd Generation i5 Processor
  • 4GB RAM
  • 1TB Hard Disk
  • 15" Screen
  • 1GB Graphics

It ships with Windows 8! ;)
However, made a dual boot upon it. Although BIOS looked different this time!!

Well,
I'm working on Ubuntu :)
Release : 11.10 (Oneiric)
Kernel Linux : 3.0.0-28-generic
GNOME 3.2.1

But Wi-Fi was not getting detected. This was not unusual, as I had set this up in earlier Dell models.
Well, the remedy is easy.
Step 1:  Make sure that you can witness the Device Card and the ID. Especially, the Network !!
Type in the following command.
$ lspci -nnk | grep Network
08:00.0 Network controller [0280]: Intel Corporation Device [8086:0887] (rev c4)

Step 2: Figure out which kernel version. This is because the driver which we will be installing works on 2.6.37 or higher
$ uname -a
Linux Swathi 3.0.0-28-generic #45-Ubuntu SMP Wed Nov 14 21:57:26 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

Step 3: Install the network manager
$ sudo apt-get install network-manager*

Step 4: Install few packages
$ sudo apt-get install build-essential linux-headers
Step 5: Check the output of
    $ dmesg
If it outputs the failure of firmware file, then its time to download the .ucode and place it in /lib/firmware.
Reboot. 
It should be working. If not, try Step 6.

Step 6: Download the compat wireless tarball from this location
http://linuxwireless.org/download/compat-wireless-2.6/compat-wireless-2012-05-10-p.tar.bz2

Extract from the tarball
$ tar -xvf <path_to_compat_wireless_bz2>
$ cd <extracted_path_compat_wireless>

Installing the packages
$ make
$ sudo make install

After this command it will show on the console the command to disable bluetooth, ethernet and Wi-Fi. Type in the 3 commands.
Place this module into the kernel.
$ sudo modprobe alx
The Ethernet LAN should be detected.
Add the driver module into this file : /etc/modules
Append the following lines. Don't touch the rest. This will enable this module while restarting the system as it loads the module.
$ sudo vi /etc/modules
#E2200 support
alx

Reboot your machine.
You must witness "Wi-Fi Networks Available!" notification on you desktop :)
Happy Learning! :)