Well, it's work in progress, and I don't think we can easily tell the strict minimal requirements for the testnet version (way more demanding because of the underlying backend).
I just ran it on an Intel(R) Atom(TM) CPU N2800 @ 1.86GHz with 2GB of RAM and HDD, and it works. Annoyingly slow, with seconds of delays, close to unusable but still. YMMV, as there are tons of various factors, including BCAK ;-)
Mainnet version however is slow, but usable on a same hardware so it should give you some perspective on the requirements.