I tell, but I preface it with "we reserve the right to change our minds -- so if you buy clothing, blankets, etc. and he/she comes out & decides not to "fit" our name, well -- too bad for you!" For some reason I was really irritated when they wrote "Ian" on the cake at the baby shower.
As for celtic names, Gavin was always at the top of my list, but dh knew a kid w/ that name (a kid he didn't like). Love Liam as well, but it was deemed too "wierd." Then my sister had a William that they planned to call Liam.
My girl names are running toward romantic... I'm loving Moira, Jocelyn... it has to fit with her middle names which will be Evonne-Dawn or Evonne-Marie (My mil's middle name and Dawn Marie is my mom) The boys both have family middle names.
If we have a boy the initials would probably have to spell something (we have IMP and ASP), and possibly start with a vowel (according to dh).