Nope. HTTPie is much, much more focused than cURL (the CLI tool). It is exclusively an HTTP client designed primarily for interactive use. cURL, on the other hand, is meant to be used mostly non-interactively and is more of a general client for "URLs" (it also supports DICT, FILE, FTP, FTPS, GOPHER, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMTP, SMTPS, TELNET and TFTP).
HTTPie's goal is user-friendliness, so it comes with features like built-in JSON support, output formatting, syntax highlighting, extensions, etc. Comparison of the two in one screenshot can be seen in the README:
I use and love httpie but I start to regret that it's written in Python as the Python platform is a very very late adopter of modern TLS standards. Even today, in 2015, it's still a hurdle to use httpie with a SNI endpoint, and forget about it making it talk to a ECDSA-based endpoint like those exposed by the free tier of Cloudflare (so called "modern TLS"). I wonder how long it will take to HTTP2 to land.
I tried a random rewrite of httpie in Go and it worked perfectly with those endpoints, as expected, and Go is getting full HTTP2 with 1.5 in June. Too bad the rewrite was still feature incomplete, when I tried it.
The situation is not ideal but more recent versions of Python (2.7.9 and 3.4) have a much improved TLS support and things like SNI work out of the box.
For older Python versions there are some additional dependencies to be installed manually (will happen automatically in next version of HTTPie):
Serves the same purpose, for sure. However, I think the interface is more intuitive/clean for json rest apis.
I usually end up using HTTPie for manual work / ad-hoc checks. And then when I script it I tend to end up using curl, because curl is available everywhere and I never need to worry if it's installed everywhere I'll want to the script to run.