Lucas' Play Room

We have a unique design challenge for Lucas' playroom. Well actually there are a few challenges for that room. First of all it is currently overfilled with boxes of his clothes, toys and other hand-me-downs that have been oh so helpful in the first couple years of his life. I really need to go through everything and keep only the essentials and pass on the rest. The room also doubles (or I should say will double) as a guest bedroom. It houses a queen sized bed, which we may downsize at some point. 

There are two windows in the room, a closet, one vaulted ceiling (over the bed). It has blue walls, lovingly painted by my sister-in-law while I was pregnant and nesting, but unable to paint myself. There is also a deeper blue wall to wall carpet, that I don't particularly like, but can't afford to replace at the moment. The room is definitely not huge, but it is the bigger of the two non-master bedrooms. We opted to give Lucas the smaller room as his bedroom, and to use the other room as a multi-purpose playroom/guest room. 

I struggle with the design for that reason. I want it to be fun and whimsical, but I don't want guests to feel like they are sleeping in the playroom! I would love to incorporate the following elements:

Transportation ABCs by Petit Collage

Repurposed coffee table, turned train table at ID Mommy

I'd actually like to make this a "drawbridge" style table, affixed to a wall for space purposes. I'd like the reverse side to be a custom art piece, that camouflages any necessary hardware. 

Corner desk as seen on Ohdeeoh

I will make a smaller version of this because I don't want these to be near the windows, Lucas' playroom is on the second floor. Or I may just put them on the long window-less wall. 

DIY Roman Blinds from Mini blinds 

I'll certainly be choosing different (light blocking!) fabric. I'll likely choose a wide-striped fabric for a less "childish" feel. 

I'd like to balance the ABC print (pictured above) with a complimentary print with a more adult feel.  The storage bench will have solid colored cushions, likely in a blue color that is a few shades lighter than the walls. 

Any one have any helpful hints? Or favorite design blogs/sites/stores? Hook a mama up!