MtGox has recently said that the "official announcement will likely be this week" on
twitter.
Also, from irc yesterday:
Apr 07 12:13:28 <owowo> MagicalTux: what's with this LTC rumor? April fools joke?
Apr 07 12:14:12 <MagicalTux> owowo: nah, we plan on adding more virtual currencies, that's a plan we had for a long time
Apr 07 12:14:34 <owowo> <3
Apr 07 12:14:51 <liteboy> btc-e just added ppc and trc yesterday, i guess its so that you guys dont tottaly take them out of the game?
Apr 07 12:15:18 <liteboy> MAgicalTux; I know LTC and NMC, are there other ones on top of those 2 you are considering?
Apr 07 12:15:38 <MagicalTux> liteboy: it depends on the strength of the devteam behind each currency and proven reliability
Apr 07 12:15:54 <MagicalTux> also depends on customer depand
Apr 07 12:15:56 <MagicalTux> demand*
Apr 07 12:16:25 <liteboy> MAgicalTux: thats awesome, i like the fact that the actual dev of the coin means something to you. So no junk coins.
Apr 07 12:16:47 <liteboy> Makes Mt.Gox strong like OX
Apr 07 12:17:01 <owowo> yeah, baby!
Apr 07 12:17:45 <liteboy> I have heard rumors that you will be making an announcment next week, is this accurate?
Apr 07 12:20:55 <MagicalTux> liteboy: yes, it is
Apr 07 12:21:18 <liteboy> MagicalTux: oh hooray. I hope its good news
Apr 07 12:21:49 * FredEE (~fehrsam@199.73.113.159) has joined #mtgox
Apr 07 12:21:55 <liteboy> MagicalTux: Do you have any spoilers you can dish out about the announcement?
Apr 07 12:22:40 <MagicalTux> liteboy: nope
Apr 07 12:22:56 <liteboy> MagicalTux: lol, hey, it was worth a try
Apr 07 12:23:58 <liteboy> MagicalTux: are you able to state wheather or not Mt.Gox is still planning LTC for this month?
Apr 07 12:25:08 <MagicalTux> liteboy: You'll see next week
Make of that what you will, but it's definitely not just a rumour.