You'll be okay to ship your game to majority of your users with a configuration like that. Even the fairly old (nearly 3 years now) old Samsung Galaxy Captivate will run with a texture resolution of that size. You won't have too many issues supporting almost any device like that (I can't think of any off the top of my head. Okay, that's a lie... maybe the HTC Drean. However, that being said if you want to prevent random crashes and the like when a user OPENS your app - do yourself a favour and query for GL_MAX_TEXTURE_SIZE. This will return the maximum texture dimension you can use and if it's less than 2048 you can throw a warning to your user stating gameplay probably won't work or you can load some alternative assets if that's possible for your game that might work for the game at a lower resolution, scale, or with some effects missing. The choice is yours!
Edit: We're in 2015 now; nearing 2016. You can safely assume most devices will support such an atlas.