So far with my 70+65+65 shamies i've done Ramps+BF+SP.

I've tried SP with the clones at 63 but 5 mob pulls with a fearer and a mind controller are a bit rough >.< At 65 it was cake(ish) just need to know what your kill order is.
I reckon at 70 it should not be a problem tho, at least not up to the level ~66ish instances (Old Hillsbrad etc)

I dont think i'll be able to do BM / SH / SL or the TK ones. And i dont think any heroics at all. (then again, i soloed SL up to the first boss on my shadow priest )

My wife has a T4/ZA geared warrior tho, and with her help i'm pretty sure it will be a breeze.
That or i'll go and whack them at level 72+ :-)