Personally, I would want one big ticket item and maybe some little fun things. That way, those things are usually things that I wouldn't easily go out and buy for myself. For a unique baby item, I found some stuff that I thought were really cool that I'd want when I have another one. Maybe you'll like them too. I don't know what your budget is so here's a handful of ideas:
1) Kiddopotamus SwaddleMe- It lets you swaddle a baby in a car seat. Very handy, if the baby loves being swaddled.
2) BundleMe- My son was fine without major swaddling and so I blanketed him up instead. I wish I would've bought one of these when he was an infant. I have a toddler one now and it's great for use in the stroller when we're outside for longer periods of time.
3) Lilliebaby EuroTote from modernnursery.com- I found this in a magazine. I haven't checked reviews or exactly how it works, but it's a soft carrier that can also be used as a bunting, stroller bag, play blanket, and travel bed. It's cute and sounds really handy.
4) Babylegs- I LOVE these. Babylegs.net sells them, or a lot of other baby boutiques do too. They're so useful for any age. I use them with my son now as leggings for the winter. They're easier to pull of when he is indoors and don't need to be removed to change diapers.
Well, if the couple is active or have a certain interest, you could try to get something that will fit that. Like a backpack carrier for hikers, or a travel playpen for big travelers, etc.
I racked my mind for newlywed gifts, but I can't really come up with anything. Maybe a cool gadget that will fit their interests?
Hope this helps! Let me know what you think and if you need more ideas.
**Edit: Here's another idea that I just saw done at a shower. Get a jar and decorate the outside and fill it with pieces of paper. It's a memory jar and it's for the mom to jot down memories of her baby. This is really cute and convenient because it's always annoying to have to find time to write down the cute thing that baby did. The papers makes this quick and easy.