Sorry, but maybe it would pay to Google things and keep on security news sites occasionally. Sure, I'm a home user for the most part, my home connections aren't liable to be attacked.
But WPA-TKIP is fatally flawed and allows - while not password revelation - replay-attacks that allow packet injection and all kinds of other nasties. Some of this has been known about since 2008. Some of this is because WPA still uses the RC4 stream cipher (which is dead nowadays) in some situations too, whereas WPA2 uses AES.
Services such as CloudCracker also mean that anything not already a seriously complex passphrase is only a couple of hundred dollars away from complete compromise - and NOBODY at home has a passphrase that complex, as you normally have to give it to people (yourself included!).
WPA / TKIP are thus dead. WPA2 / AES have measures against such things. And WPA2 hardware is old-hat now and it's been available for years. There's no excuse to still be lingering on WPA, and WEP is just asking for it - it's actually quicker to crack WEP even casually than it is to piss about asking people for their passphrase (have done it to several friends who told me they were "secure"). WPA's life is, to put it bluntly, limited at best.
Guest network - I have no need of one. I certainly have no need of one I have to turn on and off all the time. So it stays off. With modern 3G, the chances of anyone wanting to join your wireless are entirely minimal, but a lot of home routers that offer guest Wifi have associated vulnerabilities or are commercial services I have no desire to offer (BT-FON etc.).
And there are three channels on 802.11g. Three. Ignore the 13 that you might claim to be given on the router config, they overlap. And, thus, chances are that in any suburban environment, you are already picking up a ton of other networks that overlap yours. Kill off the guest networks, whatever the channel, or move to 5GHz (which is still pretty dead, but liable to get a lot busier over time).
And I VPN all my wireless. The extraneous ping is 1ms on normal hardware (and, no, I don't have particularly high-end equipment on the VPN side - usually some old crappy desktop running Linux). You can test this quite simply with even the simplest ping to Google using the Linux tools that will show sub-ms pings as proper floats. VPN costs are extremely minimal. Gaming is NOT affected any more than anything else. In fact, bulk download/uploads are liable to have more of a delay than tiny regular packets.