Why haven't the Guaranteed banks been split in to their parts?

Just curious as to why AIB and BOI haven't been broken in to their Saving, Investments and Loans divisions?

Now that they have been nationalized and with the debt guaranteed any way doesn't maintaining them as single entities endanger the only profitable parts left? Also doesn't the looming threats of the Loans division endanger the depositors division, not to mention that migration of deposits away from the state on account of this.

What reason for not breaking the overall problem in to it's constituent parts, investors have already ran anyway, what's left to lose?

Also just to ask, with shares at an all time low, and the banks guaranteed by the govt, what are the actual dangers of losing your investment were you to buy these shares?
I realize it's extremely high risk, but I'd like to quantify and understand the nature of it, as from a gamblers perspective, if your willing to place what your willing to lose and they survive, then chances are you could get a nice return.......remember here tho, I'm not advocating investment in saying this, merely pondering the ins and outs of taking a punt....