Did you guys here about this? I got it from International VIP site and there is NO a confirmation by YG. Linda is the admin.
At the Big Bang Alive Concert in Hong Kong supposedly GD talked about Big Bang's enlistment plans
‎[BigBang Enlisting] > Updated
GD had spoke about it during the Alive concert in Hong Kong.
YG is currently arranging for the debut of new bands to fill the space up when BigBang enlist.
G-Dragon said that they don't have to enlist now. BigBang are already at their 25, 26 years of age (at their enlistment ages)
It can't be prevented because as guys, they have to take this responsibility and is compulsary - They said 2 years will pass soon.
2013: TOP will go
2014: GD+Taeyang will go
2015: Daesung will go (TOP returns)
2016: Seungri will go (GD+Taeyang returns)
2017: Daesung returns
2018 Seungri returns
~ As from 2013 we can still see our BigBang members however it is not until 2018 that all 5 members will be united
! I will update if anymore news and will post a video if I can find one
-Linda

SOURCE: http://forums.allkpop.com/threads/rumours-bigbangs-enlistment.89053/

                http://360allkpop.blogspot.com/2013/01/will-big-bang-leader-g-dragon-enlist.html

this isnt the only site claiming this, but we're still not sure if it's true, if it is, there's a possibility Big Bang's not gonna have a comeback this year, because they all might leave with tabi.

so we have the option of 5 years with solo activity from each member,

or 2 years of no Big Bang activity at all

personally, the second appeals to me more, and i'm seriously tearing up at this, bcuz theyre my first group and i was so looking forward to my babies' comebacks that might not even come...

this just ruined my day, my week, and the next two years for me. it's like half my life is enlisted in the army.

i knew this day was inevitable, but i didn't know it would be here so soon.

how will us VIP's survive without our Kpop Kings?

p.s If I find out these allegations are true, do be expecting  Big Bang picture spams :'(