IPv4 will work just fine for your lifetime, or at least certainly beyond any possible use of Windows 98. Don't worry about it.

While the Feds had the goal of converting everything to IPv6 (everything meaning all of their own networks), by last week, that only meant the *ability* to handle IPv6, not that it had to be used, nor that IPv4 could not be used. In fact, IPv4 and IPv6 will coexist for a long time, and in the meantime, hardware and software will be prominently developed to handle both.

If you want to read about it, try this Google search:
http://www.google.com/search?num=30&hl=en&newwindow=1&safe=off&q=ip4+ip6+transition

Or just accept this more simple explanation:
http://en.wikipedia.org/wiki/IPv6

"As of May 2008, IPv6 accounts for a minuscule fraction of the live addresses in the publicly-accessible Internet, which is still dominated by IPv4.[7]
"With the notable exceptions of stateless auto-configuration, more flexible addressing and Secure Neighbor Discovery (SEND), many of the features of IPv6 have been ported to IPv4 in a more or less elegant manner. Thus IPv6 deployment is primarily driven by IPv4 address space exhaustion, which has been slowed by the introduction of classless inter-domain routing (CIDR) and the extensive use of network address translation (NAT)."

IPv4 exhaustion

 Main article: IPv4 address exhaustion
Estimates as to when the pool of available IPv4 addresses will be exhausted vary widely. In 2003, Paul Wilson (director of APNIC) stated that, based on then-current rates of deployment, the available space would last until 2023.[8] In September 2005 a report by Cisco Systems, which is a network hardware manufacturer, reported that the pool of available addresses would be exhausted in as little as 4 to 5 years.[9] As of November 2007, a daily updated report projected that the IANA pool of unallocated addresses would be exhausted in May 2010, with the various Regional Internet Registries using up their allocations from IANA in April 2011. [10]

At the point at which the RIR and IANA pools are exhausted, while there would still be unused IPv4 addresses, the existing mechanisms for allocating those addresses would no longer be capable of being applied, and it is at the moment unclear as to what those mechanisms might be. Mechanisms that have been discussed for allocating IPv4 addresses beyond this point have included the reclamation of unused address space, re-engineering hosts and routers to allow the use of areas of the IPv4 address space which are currently unusable for technical reasons, and the creation of a market in IPv4 addresses."