Its not a deal breaker at all for me. i have a 16 Gb phone and i have 10 gb left. I have most of my contents on the cloud like music, books and some files.
fyi, sd card are slower than the internal flash storage.
How do you use the cloud?
I would also love to have enough space for everything, especially since I had a 16GB card *almost* full (back before I lost everything on it). Not having a memory card slot would've been a deal breaker ordinarily, however, I've been hearing nothing but good things about the Galaxy Nexus, so I may keep it in mind.