The arrival of Microsoft’s OneCare has been flagged up for so long that market leader Symantec was able to announce its response – codenamed Genesis – a few hours before Microsoft’s own announcement went out.

Windows OneCare will be released in June. Home and small office users can buy the software over the web or in stores for $49.95 for a one-year three-seat subscription. That compares to annual three-seat licenses of $119.95 from Symantec and McAfee and $89.99 from Trend Micro. Symantec and McAfee sell single-seat subs for $69.95 a year, while Trend’s also sells for $49.95.

OneCare will feature antivirus, firewall, anti-spyware, PC maintenance tools, and backup. It does not appear to include anti-spam, which can be found in rivals’ suites.

Support via email, phone and text chat will be free, Microsoft said. From its three major competitors, only Trend offers free phone support. Symantec charges $29.95 per incident.

The news was not wholly unexpected. Many expected Microsoft to arrive in the $50 ballpark. The fact that it is offering the two additional seats for no added cost was less expected, and may provoke a response from rivals.

The news had little impact on the share prices of Symantec, McAfee and Trend on the day of the announcement. All three stocks shuffled around normally, gaining or losing little ground.

While none of them are talking about lowering prices just yet, the leading security companies have time to make sure their competitive strategies are in place, now that almost all of Microsoft’s cards are on the table.

Notably, Symantec has outlined a product strategy that, depending on how you look at it, either mimics Microsoft’s strategy or targets the same consumer demand for an integrated security/maintenance product.

Norton Genesis will include all the features of Norton Internet Security, plus the SystemWorks maintenance and backup capabilities that will enable users to back up their documents locally or over the internet to Symantec servers.

It will also incorporate intrusion prevention technology the company recently acquired when it bought WholeSecurity.

Symantec also said that the company has no plans to discontinue the existing products such as NIS or Norton AntiVirus or SystemsWorks. However, some suggest the availability of combined products such as OneCare will hit sales of separately packaged applications.

Attention now turns to the channel. While retail is still important, desktop security companies are increasingly focused on getting in front of consumers earlier, whether through PC makers or service providers.

It remains to be seen whether Microsoft can leverage its strong relationships with PC OEMs, where it sells Windows, to push security add-ons. The bigger PC makers already make tens of millions of dollars every year by selling antivirus software.

There’s the added issue that whenever Microsoft uses OEM deals to push non-OS software, it runs the risk of attracting regulatory attention. Its decision not to bundle OneCare with Windows is seen by some as a response to these types of concerns.

In the service provider space, chances are Microsoft will leverage its Hotmail, MSN and Windows Live branded services to push OneCare. In the case of Hotmail, that is likely to push out Trend Micro, which supplies virus-scanning now.