Spiegel said:
New Play Control! Mario Tennis 01/15
Haruhi Suzumiya no Gekidou 01/22
Fragile: Farewell Ruins of the Moon 01/22
Final Fantasy Crystal Chronicles: Echoes of Time 01/29
Another Code R: Gateway of Memory 02/05
Dead Rising: Chop Til You Drop 02/19
One Piece Unlimited Cruise: Episode 2 02/26
New Play Control! Pikmin 2 03/12
Phantom Brave: We Meet Again 03/12
Jikkyou Powerful Pro Baseball Next 03/19
Suzumiya Haruhi no Heiretsu 03/26
Releases were consistent in the first quarter. It's just that they sold poorly and did nothing for the hardware.
From your list, I see the same type of games and Monster Hunter G. If the MH3 demo doesn't bump the hardware nothing will do it until the release of Wii Sports 2.
Well, most of those games didn't/won't go on to sell a considerable (>90-100K) amount, as most of the PS3's 'big hitters' did. I tried to revise your list to include titles that may hit around that threshold:
New Play Control! Mario Tennis 01/15
New Play Control! Pikmin 2 03/12
One Piece Unlimited Cruise: Episode 2 02/26
New Play Control! Pikmin 2 03/12
Jikkyou Powerful Pro Baseball Next 03/19
It's definitely a respectable amount of games, but comparing these releases to the PS3's is strange because most of these aren't 'new' games that can rope in more customers. One Piece already had its first episode released (which is tracking higher than Episode 2 atm), Power Pro is in a similar situation where the console had already seen some releases (which are still strong on PS2) except it isn't tracking behind the previous games. Then you have the NPC games, which definitely have appeal to non-GC owners, but I have a hard time imagining a large amount of people wanting a Wii to play updated GC games.
When compared to the PS3's releases of: RE5, Yakuza 3, and SFIV, the series' first next-gen sequels and WKC and Demon's Souls, original RPGs, most of which have far outsold the ltd's of the previously mentioned Wii games, its hard to say the Wii has experienced as consistent an amount of 'system-selling' software as the PS3.
edit: the upcoming releases look slightly more comparable. MHG/3 are going to be the series' first releases on the Wii much like the PS3's Q1 software, and ARF, an original RPG, may do well (70-100k) based off of Imageepoch's recent success, it being a 'traditional JRPG', as well as previous JRPGs doing somewhat respectable numbers on Wii (ToS2, Rune Factory).