Do I really need Microsoft .NET Framework 4 Client Profile

[#1]

Microsoft .NET Framework 4 Client Profile for Windows 7 x64-based Systems (KB982670)
Download size: 45.7 MB

The Microsoft .NET Framework 4 Client Profile provides a subset of features from the .NET Framework 4. The Client Profile is designed to run client applications and to enable the fastest possible deployment for Windows Presentation Foundation (WPF) and Windows Forms technology.

[#2]

Try doing without it and see if anything important breaks.  
I'd guess not.
Don't think it's on my W7x64 system, but I'll go and check shortly.
Edit: Optional, not installed. 

[#3]

Will it appear in the next Service Pack for Vista? 
can`t imagine what it does, or why itshould be considered as an "important" update for me......

[#4]

On my W7 64 bit  it is classed as important

[#5]

Classed as important  recommended on my W7, Ive installed it as i wont be upgrading to service pack one when its available.

[#6]

its recommended/required because any developers who build on .net (im sure theres a few hundred thousand) could start using the updated version... obviously you'll need the updated libraries too - else you wont be able to use their apps, and you'll get crappy errors)
i believe you can uninstall the old .net frameworks tho ? but i may be wrong

[#7]

On the rare occasion when I've installed an application that requires .net it has also supplied a copy to install.
(well, to be honest I have in the past seen some "lazy" stuff from Microsoft itself that just tells you to install it)
On that basis I generally leave it out of systems that I have until it is specifically required; it's caused no problems whatsoever over however many years .net has been around.