I am very aware of savings. I guess as I am not socking away tens of thousands each year, I just don't stress over having to pay taxes and figure it's part of life. I am married to a UKC so the majority of savings are in his name alone, so only get taxed by the UK.
We are also quite cylical in our savings. Save a lot..buy a house....save some more...spend it on a wedding. So far nothing except pensions have been very long term. We have only just started focusing on long term savings and Cash ISAs and Savings accounts were the best we could come up with. HSBC have their Regular Savers account, which is offering 10% interest at the moment. I haven't worked out all the details, but certainly seems like a great idea - even if you have to pay 40% US tax, that is still a 6% return after tax.
As far as retirement goes, I have a pension with my company and a Roth IRA back in the US that I put a few hundred dollars in each year (christmas and birthday gifts). Nothing majorly exciting.
When we get to the next level of savings (i.e. £15,000+ a year) we will speak to a qualified tax/financial advisor regarding our best options for expat situations.