None of the shapes has changed, only the names have.
So, your C (3000) is now a D. Your B (2234) is a C. And so on. If you're playing by yourself it's no worries. If you're in a group you have some transposing to do.
Yes, the same chord shapes. Since every string is tuned one whole step up from standard GCEA, when you play the fingering for a G-major chord (standard tuning) the pocket uke will play an A-major chord.
For many years on the U.S. mainland, ADF#B was considered standard soprano tuning. Many players still prefer to tune sopranos this way.
If you're playing alone and not concerned about what key you're in, just play the pocket uke the same as you play a GCEA uke. You'll be playing in a higher key, that's all. If you're playing with others then you'll need to play the correct chords, which means learning the new chord chart or transposing on the fly.
Thanks for the info! I just started a couple of months ago so I'm still learning. I have a Mainland concert but picked up a pocket uke because....heck, its adorable. As a beginner, I didn't want to venture into transposing just yet so I'm glad that I can still use the same chord shapes and that they're just a step higher.
I actually got one off ebay from Bruce Wei. It was a pretty good price for a solid acacia koa pocket uke, looks great, and after a set up it plays well too...at least to my ears, but then again, I'm fairly new to ukes so that's probably not saying much.