depends on your program and how your unit(s) are set up. at the palo alto VA, there's a combined med-surg ICU with an ICU fellow, 3 residents (1 med, 1 surg, 1 anesthesia) and 3 medicine interns. over at stanford, there are 3 different unit teams - MICU, SICU and CVICU. MICU has an ICU fellow and 3 residents (1 med, 2 anesthesia) who act as interns. CVICU is basically 1 anesthesia attending and 1 anesthesia resident with help from the cardiac anesthesia fellows. don't know how the SICU works.
the unit is much more intense and things (and patients) can go sour in the blink of an eye. as long as you're not doing the unit early on in your CA-1 year, you should probably be ok. there are usually a decent number of procedures but the rounding (and pre-rounding) can be very, very painful.