Tier 2 ICT to Tier 2 general switching - dependent query

[jituce]

Dear friends,

I am presently working in the UK on a Tier 2 ICT long term VISA that was issued to me in Jan 2010.
I have been in the UK from Jan 2010 working on the same VISA and recently extended until Feb 2015.
I have a sponsor willing to sponsor my Tier 2 General VISA via an
unrestricted COS, can you please confirm if I would be able to
switch in to a Tier 2 General VISA in-country, without needing to
go back to my home country.
Would you please be kind enough to confirm if this information is
accurate, and if I will indeed be able to switch my VISA
in-country.
Also would my dependant / spouse (presently as Tier 2 partner) also
need to change their VISA - if yes, would that be done in-country
as well please ?