They do look VERY similar, it's quite bad of Mac really to release 2 lipsticks in the same year with both cremesheen finishes. Naughty, but I'm not complaining. :)
When swatched they look very similar, Ever Hip is a tinge more pink, but essentially they are the same colour even when applied to the lips. You really can't tell them apart, if you want to be fussy then Jazzed has a slightly more muted finish.
Do I need both? No.
Do I want both? Yes.
Why? Different packaging, the slight tone difference is enough for me to justify having both because I'm greedy, plus they are both limited edition and are VERY pretty colours perfect for Summer.
I also did a swap with the gorgeous Ebru, I was having withdrawal symptoms over the Maybelline dream SMOOTH mousse aka Dream Creamy in the UK. The shades we have in the UK are rubbish compared to the US. My shade is Natural Beige.
She also sent me the NYC creme stick (blush) in 'Plaza Pink' which is very beautiful, the consistency isn't greasy making them perfect for hot weather, I would highly recommend you check them out if you are in the US as they are fantastic value for money. She also sent me a NYX lipgloss in 'Smokey Look' and a jumbo pencil in 'Milk'.