Question about IVY bridge vs Sandy bridge...

Ivy Bridge is a CPU microarchitecture which will be sort of an upgrade fom Sandy Bridge.
Your i5 will be outdated only in a date of release kind of way. It will last you a few years probably since it's a good CPU.
About the performance increase it's hard to tell because Ivy Bridge isen't out yet but you can search the internet ( and our forum) for speculation

so if Ivy B is an upgrade from sandy E chip then does that make my 3930K a sack of crap when ivy B comes out and that ivy will be faster then ?

this link might give you a rough idea.
http://en.wikipedia.org/wiki/Ivy_Bridge_(microarchitecture)
ivy bridge is mostly cpu. it will have it's own mobo chipsets (so far z77, z75 and h77) but it'll fit the same lga 1155 socket found in sandy bridge motherboards (well, most of them - b and q series chipsets don't support ivb).
your cpu doesn't become outdated after ivb release. intel is promising (and from the leaks and previews so far) roughly 7-15% improvement on cpu side. most of the improvements will go to igpu side which seems to be up to 60% faster and supports latest technologies.
2550k is an unlocked sb cpu, it'll serve you for quite some time.

The IB CPU is unlikely to make the SB obsolete for gaming any time soon. There are currently available SB models (the i7s 2600K & 2700K) which are overkill for gaming. Even the SBe processors are too much to be overwhealmed by current games. So, if your target is gaming the SB is a solid platform for the next couple of years.

Is the SB already obsolete? To a certain purpose: yes. For those who have unlimited budgets and want the fastest, most powerful rig they can buy the SBe is more powerful, as the IB may outclass the SBe.

From what I could gather you'll be missing out on .1 ghz more speed and a wireless ability to transmit to your TV. And of course you'll pay more $ for that. So, meh.

Pff, I hope that's righyt. Who cares? I'll just oc to .1 GHz more   And oh ya, I have a TV tuner so I can already do that  

There is no point of upgrades, as I assume you bought the 2500k for games. Since almost everygame now is more gpu than cpu dependent ivybridge offers no performance upgrade over sandy in terms of gaming.

Sandy bridge CPU's are built on a 32nm process.
Ivy bridge is built on a smaller 22nm process with mostly the same architecture as sandy bridge.
At launch, it will probably be about 10% faster than the same priced sandybridge, and will probably overclock a bit better.

If you currently own a sandy bridge cpu, there is no compelling reason to change unless your current cpu is not fast enough.

There will be a companion Z77 chipset, and associated motherboards which may offer a few added capabilities, but I have not seen any features that are game changers.

If a build time frame will extend to IB launch, then most people will go with IB. Do not expect the launch to cause a run on SB prices.