teaskeptic wrote:I believe it's called the placebo effect :p
You must be short on experience
(I'm kidding around, I mean no offense.)
Tea is going to taste different as it cools, which can also affect the aroma, and the shape of the cup can make a difference in how the aroma rises from the liquid (if it didn't then we wouldn't have so many different kinds of wine glasses). Also keep in mind that the majority of what we experience as taste is actually smell. The shape is also going to be a factor because it can change where your nose is in relation to the rest of the cup.
Different cups can definitely have an affect on the tea, even though it's not going to change the tea itself. I have some cups that bring totally different aspects to the forefront, making it smell noticeably different.
Since antique cups are very likely made differently, and definitely with different clay, it's not unreasonable to think that they would change the tea slightly. It's not going to make it taste and smell like a completely different tea, but it can and will have an effect that can sometimes be noticeable.