The 1650mAh battery that the Samsung Focus S comes with is fairly typical for current smartphones, perhaps even slightly on the smaller side. Still, it manages very well, likely due to the fact that it's powering a single core 1.4GHz processor.
The specs claim that the Focus S is capable of up to 9 hours of talk time and a whopping 25 days in standby. We couldn't find anyone willing to talk on the phone with us for 9 hours, but we were pretty impressed with the overall battery life we got.
Even under fairly heavy use (meaning an hour or two of GPS navigation, some music playback, a few phones calls, a handful of text messages, and quite a bit of web browsing), we still had a solid 45% left after a 12-hour day.
On the days when we weren't quite so demanding, the battery would still be around 85% at the end of the day.
It of course has all of the usual connectivity features such as Wi-Fi (both 2.4Ghz and 5.0GHz, which is impressive), Bluetooth (though lacking file sharing), and GPS. No NFC onboard, but we're still waiting for that to catch on.
One of the biggest disappointments is the data connectivity. The Focus S is a "4G" phone, but barely. It uses AT&T's HSPA+ network, which at least in the San Francisco Bay Area, never seems to come close to 4G speeds.
Despite handfuls of speed tests all over the bay, we never once broke 2Mbps. That's pretty appalling even by 3G standards. The phone itself is supposed to be capable of 21Mbps under ideal conditions.