YES LTC will overtake BTC.

It will be a while till LTC overtakes BTC.

BTC will get scammed out of its socks with a decent ASIC attack.  The more BTC gains in value to more likely a 51% attack is.  I recall people getting all giddy about BTC passing $100, then $125, ...$200.  I kept on saying cool but tried reminding people that as BTC gains value it is more susceptible to Murphy's Law, and I was proved correct.  Attackers and the pure suckiness of Mt.Gox killed a pretty decent rally.  But who nows maybe the rally getting killed in BTC is good for BTC.

The recent DDOs attacks have been handled pretty well by the market which to me means that soon a pure DDOS attack on Gox will not derive enough benefit for the attackers so they will have to change strategies.  ASIC is the next most likely strategy coupled with DDOS.  Then again noting happening is also a likely possibility.

Once LTC is traded on GOX LTC will begin to slowly siphon value away from BTC and LTC will begin to gain parity with BTC.  Yes Gox is still the first 51% attack on BTC and the only likelihood of a 51% attack on LTC.

I do say that LTC should have been better named, but oh well.  I do still enjoy all the projections about how LTC's coin count being 4x BTC that this fact somehow means LTC's total market cap is 1/4 BTC.